The difference between I-beam and H-beam
What is H-beam?
Table of Contents
- What is H-beam?
- Features of H-beam
- Classification of H-beam
- How many kinds of H-beam diameters are there?
- Material of H-beam
- Size of H-beam production specifications
- Production method of H-beam
- The use of H-beam
- Common defects of steel sections and control methods
- What is I-beam?
- The difference between I-beam and H-beam
- Which is stronger, H-beams or I-beams?
- How to find the right supplier of section steel?
The cross-section of H-beam usually consists of two parts: web and flange, also called waist and edge.
H-beam is an economic section and efficient structural steel with more optimized cross-sectional area distribution and more reasonable strength-to-weight ratio, named because its cross-section is the same as the letter “H”. Since all parts of H-beam are arranged at right angles, H beam has the advantages of strong bending resistance in all directions, simple construction, cost saving and light weight structure, etc., and has been widely used.
Features of H-beam
The thickness of the web of H-beam is smaller than that of a normal I-beam with the same height of the web, and the width of the flange is larger than that of a normal I-beam with the same height of the web, so it is also called a wide flange I-beam. Due to the shape, the cross-sectional modulus, moment of inertia and corresponding strength of H-beam are significantly better than those of ordinary I-beam with the same single weight. H-beam has wide flange, thin web, many specifications and flexible use, which can save 15%-20% of metal in various truss structures. Since the flanges are parallel on the inside and outside, and the ends of the flanges are at right angles, it is easy to assemble and combine into various members, thus saving welding and riveting workload by about 25%, which can greatly accelerate the construction speed of the project and shorten the construction period.
- Wide flange and large lateral stiffness.
- Strong bending resistance, about 5% – 10% higher than I-beam.
- The two surfaces of the flange are parallel to each other, making the connection, processing and installation simple.
- Compared with welded I-beam, it has low cost, high precision, small residual stress, no need for expensive welding materials and weld detection, and saves about 30% of the steel structure production cost.
- Under the same section load, the weight of hot rolled H steel structure is 15% – 20% less than that of traditional steel structure.
- Compared with the concrete structure, the hot rolled H steel structure can increase the use area by 6%, reduce the dead weight of the structure by 20% – 30%, and reduce the design internal force of the structure.
- H-shaped steel can be processed into T-shaped steel, and honeycomb beams can be combined to form various cross section forms, which can greatly meet the requirements of engineering design and production.
Classification of H-beam
There are many product specifications of H-beam, and the classification methods are as follows.
- (1) According to the width of the product flange is divided into wide flange, medium flange and narrow flange H-beam. The flange width B of wide flange and medium flange H-beam is greater than or equal to the web height H. The flange width B of narrow flange H-beam is approximately equal to one-half of the web height H. The flange width of narrow flange H-beam is approximately equal to the web height H.
- (2) According to the product use, it is divided into H-beam, H-beam column, H-beam pile, and very thick flange H-beam. Sometimes parallel-legged channels and parallel-flange T-beams are also included in the range of H-beams. Generally, narrow flange H-beam is used as beam material, and wide flange H-beam is used as column material, according to which there are beam H-beam and column H-beam.
- (3) According to the production method, it is divided into welded H-beam and rolled H-beam.
- (4) According to the size specification, it is divided into large, medium and small size H-beams. Usually, the products with web height H above 700mm are called large, 300-700mm are called medium, and those less than 300mm are called small. By the end of 1990, the world’s largest H-beam web height of 1200mm and flange width of 530mm.
Internationally, the product standards of H-beams are divided into two categories: imperial system and metric system. The United States, Britain and other countries use the imperial system, China, Japan, Germany and Russia and other countries use the metric system, although the imperial system and the metric system use different units of measurement, but most of the H-beam with four dimensions to indicate their specifications, namely: web height h, flange width b, web thickness d and flange thickness t. Although the size of the H-beam size specifications of the world’s countries expressed in different ways. But the range of product size specifications and size tolerances produced do not differ much.
How many kinds of H-beam diameters are there?
The diameters of H-beams are divided into eight categories, namely 3-3.5mm, 4-4.5mm, 5-6mm, 7-8mm, 9-10mm, 11-12mm, 13-14mm and 16+.
Material of H-beam
H-beam is one of the most commonly used structural steels in the world, but also one of the most diversified profiles. It can be used to make anything from bridges and skyscrapers to knives and forks. The H-beam you choose for your project will depend on its intended use and various other factors. In this guide, we will introduce the uniqueness of different metal materials of H-beam, so that you can determine which metal material of H-beam is most suitable for your needs.
High carbon steel
High carbon steel is used in springs and dies. High carbon steel has a low resistance to corrosion; its hardness makes it brittle and it can be deformed by cold working.
High carbon steel is made of iron with a high content of carbon, which imparts it superior strength and hardness, but at the expense of ductility (the ability to be stretched or bent).
High carbon steel is used mainly as an alloying element because its properties do not change much when alloyed with other metals such as manganese or nickel.
Low carbon steel
Low carbon steels are used for general construction and low-stress applications. They are less expensive than high carbon steels, but still offer good weldability. Low carbon steel is easier to form than high carbon steel, making it perfect for fabrication work such as shipbuilding or building bridges.
Stainless steel is a type of alloy steel that contains at least 10.5% chromium, often 14%, by weight. The name, coined by Harry Brearley in the 1920s, has been commonly used since then to describe this family of iron-chromium alloys. In comparison with standard carbon or non-stainless (alloy) steels, stainless steels have higher strength and hardness. These features allow better resistance against external factors such as frost/freezing temperatures, mechanical impact and abrasion from sand and gravel particles.
The following are the three types:
Austenitic stainless steel – This class includes those containing 18% chromium content or more but less than 30%. It is the most common type of stainless steel because it provides good corrosion resistance at low cost when compared to other types such as martensitic or duplex types which require special materials processing techniques (i.e., cold rolling).
Dual-purpose steel is used for high-temperature applications such as steam boilers, heat exchangers and pressure vessels. It has a fine grain structure with uniform carbon distribution and low hydrogen content.
Due to these properties, dual-purpose steel has high strength at elevated temperatures and good toughness at low temperatures. Therefore, it can be used in a wide range of service conditions (from cryogenic to moderately high temperatures). The material can also be used in both structural applications at ambient temperature up to 450°C as well as pressure vessel construction up to 550°C.
Tool steels are used to make tools and dies. They are hardened by quenching and tempering, which means that they have a high carbon content (more than 1%).
Tool steels can be further classified as:
High-speed steel: made from tungsten, molybdenum and chromium, this type of tool steel will have a higher hardness compared to other types of tool steel. These types of tools can be used for high-speed machining applications such as cutting metal or plastic at very high speeds.
The best way to determine which H section steel is right for your job is by consulting with a professional. They’ll be able to give you all the information you need and ensure that they use the right type of metal material every time.
Size of H-beam production specifications
H-beam is a common structural steel. The normal size of H-beam is the same as that in conventional section and can be used in various fields.
- The thickness: 10mm-200mm;
- The width: 1000mm-6000mm;
- The height: 1000mm-6000mm.
Dimensions of hot-rolled H-section steel
H – height; B – width; T1 – web thickness; T2 – flange thickness; R – Process fillet
|Type||Model (Height × Width)||Section size/mm||Cross-sectional area/cm2||Theoretical weight/kg·m-1||Section characteristic parameters|
|H×B||t1||t2||r||Moment of inertia/cm4||Radius of inertia/cm||Section modulus/cm3|
|HW Wide flange||100×100||100×100||6||8||10||21.9||17.2||383||134||4.18||2.47||76.5||26.7|
|Type||Model (Height × Width)||Section size/mm||Cross-sectional area/cm2||Theoretical weight/kg·m–1||Section characteristic parameters|
|H×B||t1||t2||r||Moment of inertia/cm4||Radius of inertia/cm||Section modulus/cm3|
|HM Middle flange||150×100||148×100||6||9||13||27.25||21.4||1040||151||6.17||2.35||140||30.2|
|Type||Model (Height × Width)||Section size/mm||Cross-sectional area/cm2||Theoretical weight/kg·m–1||Section characteristic parameters|
|H×B||t1||t2||r||Moment of inertia||Radius of inertia||Section modulus|
|HN Narrow flange||100×50||100×50||5||7||10||12.16||9.54||192||14.9||3.98||1.11||38.5||5.96|
Dimensions of hot-rolled H-shaped steel columns (excerpted from GB/T11263-1998)
|Type||Type (Height × Width)||Section size/mm||Cross-sectional area/cm2||Theoretical weight/kg·m–1||Section characteristic parameters|
|H×B||t1||t2||r||Moment of inertia||Radius of inertia||Section modulus||Surface area/m2·m-1|
Production method of H-beam
H-beams can be produced by either welding or rolling methods. Welded H-beams are made by cutting strips of suitable thickness into suitable widths and welding the flanges and webs together on a continuous welding unit. Welded H-beams have the disadvantages of large metal consumption, not easy to ensure uniform product performance, and restricted size specifications. Therefore, H-beams are mainly produced by rolling method. In modern steel rolling production, the universal rolling mill is used to roll H-beams, the web of which is rolled between the upper and lower horizontal rolls, while the flange is rolled and shaped between the horizontal roll side and vertical rolls. As only the universal mill can not yet apply pressure to the edge of the flange, so it is necessary to set up after the universal frame edge-rolling machine, commonly known as edge-rolling machine, in order to give pressure to the edge of the flange and control the width of the flange. In the actual rolling operation, the two racks as a group, so that the rolling reciprocal through a number of times (Figure 2a), or so that the rolling by a few universal stand and a couple of rolling edge end of the seat of the continuous rolling unit, each time to apply a certain amount of pressure, the billet rolled into the required specifications for the shape and size of the product. In the flange part of the rolled part, due to the sliding between the horizontal roll side and the rolled part, the wear of the roll is relatively large. In order to ensure that the rolls can be restored to their original shape after re-turning, the sides of the upper and lower horizontal rolls of the roughing mill set and the surface of the vertical rolls corresponding to them should be 3°-8° of inclination. In order to correct the finished flange inclination, set the finished universal mill, also known as universal finishing mill, the horizontal roll side and horizontal roll axis perpendicular or have a small inclination angle, generally not more than 20′, vertical roll is cylindrical (Figure 2d).
H-beam rolling with universal rolling mill, rolling section can be more uniform extension, flange inner and outer roll surface speed difference is small, can reduce the internal stress and shape of the product defects. Appropriate changes in the horizontal rolls and vertical rolls of the universal rolling mill under the amount of pressure, you can get different specifications of H-beam. Universal rolling mill roll shape, simple shape, long life, roll consumption can be greatly reduced. The biggest advantage of universal mill rolling H-beam is: the same size series only the thickness of the web and flange size is changed, the rest of the size is fixed. Therefore, the same series of H-beams rolled by the same universal hole type has a variety of web and flange thickness size specifications, which greatly increases the number of H-beam specifications and brings great convenience for users to choose the right size specifications.
In the absence of universal rolling mill, sometimes in order to meet the urgent needs of production and construction, the ordinary two-roller mill can also be equipped with vertical roller frame, the composition of universal hole type rolling H-beam. H-beam rolling in this way, the product size accuracy is low, the flange with the web is difficult to form a right angle between the high cost, less specifications, rolling H-beam with columns is extremely difficult, so not many users.
Manufacturing process flow of welding H-shaped steel
Rolling methods of H-beams
The rolling methods of H-beams are roughly divided into three categories in historical order.
- Rolling methods utilizing an ordinary two-roller or three-roller type section steel mill.
- Rolling methods using a universal rolling mill.
- The use of multi-stand universal rolling mill rolling method.
1. The use of ordinary two-roller or three-roller section steel rolling mill rolling method
This is one of the oldest rolling method, the first H-beam is rolled using this method. This rolling method is mostly used in the production of ordinary I-beam straight rolling method, oblique rolling method and bending diagonal rolling method production process. This rolling method can only roll small specifications of H-beam, due to the complex diagonal matching hole guide device, mill adjustment is not easy to control, low production efficiency, unstable quality, the biggest drawback is that it can not produce more than medium-sized wide leg H-beam.
2. The use of a universal rolling mill rolling method
The hole design of this rolling method is the same as the hole design when rolling ordinary I-beams. Its main feature is the use of two-roller open billet machine and two three-roller mill for rough rolling, with a universal mill for finishing. The disadvantage of this method is that the roll wear fast and not easy to recover, a small amount of rolling out, more unsuitable for rolling a variety of sizes of H-beam.
3. The use of multi-stand universal rolling mill rolling method
H-beam rolling with multi-stand universal rolling mill, universal rolling mill in addition to being driven by the upper and lower two horizontal rolls, the horizontal rolls on both sides of the passive vertical rolls, a common four rolls to form a hole pattern. Universal rolling this method has been commonly used in the world.
(1) Green’s method. Green’s method of rolling is characterized by the use of open universal hole pattern, waist and leg processing is carried out simultaneously in the open universal hole pattern. In order to effectively control the quality of the leg height and leg processing, Green’s method believes that the vertical pressure must act on the leg end, so the compression of the leg height is placed in a two-roller type stand running in continuous rolling with the universal stand. At present, the world’s edge-rolling machines mostly use this method. Its general process is as follows: with the primary rolling mill or two-roller open billet machine to roll the ingot into a shaped billet, and then the shaped billet sent to the universal roughing mill and edge rolling machine for reciprocal continuous rolling, and in the universal finishing mill and edge rolling machine reciprocal continuous rolling into finished products.
(2) Sark method. Sack method is closed universal hole type, in the hole type in the leg is inclined configuration, in order to be able to finally roll the horizontal straight leg section, must be placed in the last course of the universal stand of cylindrical vertical roll. Sack method of vertical pressure and Green method is different, it is the pressure on the leg width direction, and this is easy to cause the movement of the rolled parts, especially in the closed hole type often due to fluctuations in the size of the incoming material, resulting in the leg end projection is easy to extrude outward to form ears, affecting the quality of the finished product. In the Sark method of rough rolling universal hole type, the horizontal roll side with a larger slope, can reduce the horizontal roll wear, while the vertical roll is used with a taper, so the leg can be extended at the same time a large compression coefficient, can reduce the number of rolling passes and universal stand, saving equipment investment. The general process is: a two-roller opening machine, the ingot is rolled into a shaped billet with an I-beam section, and then the shaped billet is sent to the four-roller universal stand and two-roller vertical stand composed of reversible continuous rolling unit for rough rolling, and finally the finished product is rolled on a universal stand.
(3) Jepo method. Jephyr method combines the advantages of the above, absorbing the two advantages of the Sarko method oblique with universal hole type can obtain a large extension and Green method using vertical press hole type to facilitate control of leg width processing. The main feature of the Jephyr method is that the rough rolling adopts the Sack method of oblique matching universal hole type, and the finishing rolling adopts the Green method of open universal hole type, in the finishing universal rolling mill, firstly, the leg is flattened with cylindrical vertical rolls and horizontal vertical rolls, then the vertical rolls leave, and only the horizontal rolls press the leg end, and finally, in the second finishing universal rolling mill, the horizontal rolls and vertical rolls are used to fully process the rolled parts. The process flow is: a two-roller reversible opening machine with two tandem arrangement of universal stand for rolling, the first stand will be rolled into nearly “X” shaped shaped shaped billet, through the second universal stand for the first time, the first column-shaped vertical rolls to roll the leg straight, and then in the return pass in the neutral rolls away, only with horizontal rolls straight leg end. In the last universal rolling mill with horizontal rolls and vertical rolls on the rolled parts for full processing and forming.
4. X-H rolling method
X-H rolling method is SMS patented rolling method. The universal mill will be put into the universal stand, and the X-H rolling method is also used in the operation. The first mill adopts the X-hole design and the second mill is equipped with the H-hole type according to the final product. The four rolls of the universal mill are generally composed of two types of holes: X-hole type and H-hole type.
X-hole type rolls with a certain taper, and the horizontal rolling line as the center of the symmetry of the upper and lower. The advantages of this hole type is: conducive to the extension of the roll, the roll can be thinned quickly, and in the case of the same amount of pressure, rolling energy consumption is lower than H hole type, so in the universal roughing, rolling mill unit in the use of this hole type. H hole type vertical roll is cylindrical, finishing mill must use this hole type.
The rolls are reversible continuous rolling in X-H hole type, as the second universal mill adopts H hole type, so the finished products can be rolled directly, thus eliminating the need for finishing units, and the length of the production line is greatly shortened. the biggest advantage of X-H rolling method is: small footprint, low investment, high efficiency, and low finished products. The X-H rolling method is 55% more productive than the original single reciprocating tandem arrangement, and the roll cost is 33% lower, and it can be further transformed into the most advanced international H-beam production with near final shape continuous casting billet as raw material, using X-H rolling method of short process continuous casting and rolling technology.
X-H rolling method compared with the traditional rolling process has proven to have the following advantages in practice: higher production capacity; higher temperature level; less rolling pressure and driving power; improved roll life; temperature control rolling is possible; longer roll length. The X-H rolling method is a popular rolling method for producing H-beams in the world, and has been widely adopted by most new or newly renovated H-beam mills.
The use of H-beam
H-beam is widely used, mainly for: various civil and industrial building structures; various large-span industrial plants and modern high-rise buildings, especially in areas with frequent seismic activity and industrial plants under high-temperature working conditions; large bridges requiring large load-bearing capacity, good cross-sectional stability and large span; heavy equipment; highways; ship skeletons; mine support; foundation treatment and dam projects; various machine components.
Common defects of steel sections and control methods
1. Section steel angle filling is not satisfied
The finished hole is not filled, resulting in the lack of metal in the corners of the section steel called section steel corner filling, its surface is rough, there are local, but also through the length of the.
- (1) the inherent characteristics of the hole type, the corner of the rolled parts can not be processed.
- (2) improper adjustment operation of the mill, the amount of pressure down the distribution is not reasonable. Corner press down the amount of small, or rolled parts of the extension of the inconsistency of the phenomenon of excessive drawdown.
- (3) hole type or guide plate is severely worn, the guide plate is too wide or incorrectly installed.
- (4) low temperature of the rolled parts, poor metal plasticity, hole type angles are not easy to fill.
- (5) rolled parts have more serious local bending, re-rolling easy to produce local corner filling is not satisfied.
(1) improve hole design, strengthen the mill adjustment operation, reasonable distribution of the amount of pressure down.
(2) the correct installation of the guide device, timely replacement of serious wear of the hole and guide plate;
(3) according to the temperature of the rolled parts to adjust the amount of pressure down, so that the angles fill well.
2. Profile size oversize
Section geometry of steel does not meet the requirements of the standard requirements of the collective term. When there is too much difference with the standard size, it presents a deformity. This type of defect has a wide range of names, most of them are named by the production site and the degree of deviation. Such as out of roundness, length, etc..
- (1) hole design is unreasonable; hole wear unevenly, the old and new holes with improper.
- (2) various parts of the mill (including the guide device) is poorly installed, the safe socket rupture.
- (3) improper adjustment of the rolling mill.
- (4) uneven billet temperature, uneven single temperature produces local specifications, the whole low-temperature steel produces full-length specifications do not fit, large.
- (1) the correct installation of the components of the mill.
- (2) improve the hole design and strengthen the mill adjustment operation.
- (3) pay attention to hole wear, new finished holes, according to the specific circumstances, consider replacing the finished front hole and other related holes at the same time.
- (4) improve the heating quality of the billet to achieve uniform temperature of the billet.
3. Section steel wave
As a result of rolling uneven deformation, and produced in the local section of the steel section along the length of the undulation are called waves. There is a local, but also through-length. The longitudinal wavy undulation of the waist of I-beam and channel is called waist wave; the longitudinal wavy undulation of the leg edge of I-beam, channel and angle is called leg wave. I-beam and channel steel with waist wave, waist longitudinal thickness is not uniform, and in serious cases, a wave of metal overlap phenomenon and tongue-shaped cavity.
- (1) improper distribution of the amount of pressure down.
- (2) roll crosstalk, rolling groove wrong teeth.
- (3) the finished product before the hole or then the hole before the mill groove wear serious.
- (4) uneven temperature of the rolled parts.
- (1) in the middle of the rolling process to replace the finished hole, according to the characteristics of the product, consider the specific circumstances while replacing the finished front hole and finished before the hole.
- (2) strengthen the rolling adjustment operation, reasonable distribution of the amount of pressure, while tightening the components of the mill to prevent the rolling groove wrong teeth, so that the rolling parts of each extension uniform;
- (3) improve the quality of billet heating, to achieve uniform temperature of billet.
4. Section steel cutting defects
Various defects caused by poor cutting is collectively referred to as cutting defects. Among the hot state with flying shears when shearing small steel, the steel surface caused by varying depths, irregular shape of the scar called cut; in the hot state, the surface was damaged by the saw blade called sawing; after cutting, the cutting surface and the longitudinal axis is not perpendicular to the cut slope or sawing; rolling end of the hot rolling shrinkage part is not cut net called cutting head short; cold shear, the shear surface presents a small local fracture called tearing; sawing (shear) cut, stay on the steel end Metal flying edge on the surface is called burr.
- (1) sawing steel and saw blade (shear edge) is not vertical or rolling head bending too large.
- (2) equipment: saw blade scoop curvature, improper installation of the saw blade, the gap between the upper and lower two shear edge is too large.
- (3) operation: simultaneous shearing (sawing) too many steel roots, end excision is too little, hot rolling pulling shrinkage part is not cut net.
- (1) to improve the incoming material conditions, measures to avoid rolling head bending too much, to keep the direction of incoming material and shear (saw) cutting plane perpendicular.
- (2) improve equipment conditions, take no scoop or scoop curvature of small saw blade, appropriate choice of saw blade thickness, saw blade (shear edge) wear to be replaced in a timely manner, the correct installation, adjust the shear (saw) cutting equipment.
- (3) strengthen the operation, while cutting (sawing) cut the number of roots not too much, to avoid the rise and fall of steel, bending. Ensure that the necessary amount of end removal, the hot-rolled pulling and shrinking part of the cut net.
What is I-beam?
The I-beam is shaped like the structural steel of an I. The I-beam consists of two horizontal surfaces, called flanges, connected by vertical members or weft. The I-beam has tapered edges and gets its name from the fact that it looks like a capital letter in cross-section. For I-beams, the height of the cross-section is greater than the width of its flange.
Application characteristics of I-beam
I-beam, whether ordinary or light, because the cross-sectional size is relatively high and narrow, so the difference in moment of inertia between the two main axes of the cross-section is large, so it can only be used directly in its web plane bending members or will be composed of lattice type stress members. For axial compression members or in the perpendicular to the plane of the web and bending members are not suitable, which makes its application range has a great limitation. I-beams are widely used in buildings and other metal structures.
Ordinary I-beam, light I-beam, because the cross-sectional size are relatively high, narrow, so the difference between the two main axes of the cross-sectional moment of inertia is large, which makes its application in the scope of a great limitation. The use of I-beam should be selected according to the requirements of the design drawings.
In the structural design, I-beam should be selected according to its mechanical properties, chemical properties, weldability, structural dimensions, etc. to choose a reasonable I-beam for use.
Classification of I-beam
I-beam is mainly divided into ordinary I-beam, light I-beam and wide flange I-beam. According to the height ratio of flange to web, they are divided into wide, medium and narrow wide flange I-beams. The first two are produced in sizes 10-60, i.e., the corresponding height is 10 cm-60 cm. At the same height, light I-beams have narrow flanges, thin webs and light weights. The wide flange I-beam, also known as H-beam, has a cross section characterized by parallel legs and no slope on the inside of the legs. It is an economic section steel, which is rolled on a four-roller universal mill, so it is also called “universal I-beam”. Ordinary I-beam and light I-beam have formed national standards.
Its specifications are expressed in high x leg thickness x waist thickness, but also available to indicate the number of specifications of the main dimensions. For example, No. 18 I-beam, which means the height of 18 cm I-beam. If the height of the same I-beam, the number can be followed by an angle code a or b or c to indicate, such as 36a, 36b, 36c, etc.. It is divided into ordinary I-beam, light I-beam and wide flange I-beam. According to the height ratio of flange to web, it is divided into wide, medium and narrow width wide flange I-beam. The first two are produced in sizes 10-60, i.e. the corresponding height is 10 cm-60 cm.
Rolling method of I-beam
The types of I-beams are divided into hot-rolled ordinary I-beams, light I-beams and wide parallel I-beams (H-beams). The waist width of hot rolled ordinary I-beam produced in China is between 100-630 mm, the numbers are indicated as No. 10-63, and the slope of the inner leg is 1:6. And the I-beam hole system is divided into: straight rolled hole system, inclined rolled hole system, mixed hole system and special rolling method. Here we will introduce these hole systems separately.
- (1) Straight rolling hole system. Straight rolling hole system refers to the I-beam hole pattern of the two open legs at the same time in the same side of the roll axis, and the waist parallel to the roll axis system. The advantage is that the roll axial force is small, axial runout is small, do not need to work bevel, and hole type accounted for the roll body length is small, the roll body length under certain conditions can be more with hole type.
- (2) Oblique rolling hole system. This type of hole system means that the two open legs of Q345B I-beam hole type are not on the same side of the waist at the same time, and the waist is at a certain angle with the horizontal axis.
- (3) Mixed hole system. According to the characteristics of the mill and the product, in order to give full play to the advantages of their respective systems and overcome their shortcomings, will often use a mixed hole system, that is, a combination of two or more systems. For example, into the finished hole and finished before the hole using straight-legged oblique rolling hole type system, other hole type using curved leg oblique rolling system. Or rough-rolled holes using straight-rolled, 3-4 finishing holes using straight-legged oblique tie holes, etc.
- (4) Special rolling methods. For some reasons, it is difficult to roll the required I-beam with ordinary rolling methods. At this time, special rolling methods can be used to make full use of the uneven deformation and hole design skills. For example, when the cross-section of the billet is narrow and a wider I-beam needs to be rolled, wave rolling methods can be used; another example is when the billet is wide and a smaller I-beam needs to be rolled, negative width spreading rolling can be used, etc.
Whether ordinary or light I-beam, because of the relatively high and narrow cross-sectional dimensions, the difference in moment of inertia between the two main axes of the cross-section is large, and can only be used directly for members subjected to bending in the plane of their webs or to form them into lattice load members. For axial compression members or in the perpendicular to the web plane and bending members are not suitable for use, which makes its application is greatly restricted. Therefore, I-beam should be used in strict accordance with the requirements of the design drawings.
The use of I-beam
I-beam, with high strength and toughness, is often used to bear the main stress parts of the steel structure, I-beam performance is stable, generally through processing, such as cold-formed, cutting, welding, etc.
The standard specifications of I-beam have been used in a wide range of steel structure projects.
The strength, toughness, plasticity, corrosion resistance and weathering performance of I-beam (Q345) low-alloy material are stronger than that of carbon material, which is generally used in higher force requirements, or higher plasticity requirements, or relatively special environmental work, such as low temperature, high corrosive environment, etc.
a). the scope of application of I-beam:
- 1. Beam and column members in the steel structure of industrial and civil buildings;
- 2. Steel bearing support of industrial structure;
- 3. Steel piles and supporting structure of underground engineering;
- 4. Petrochemical, electric power and other industrial equipment structures;
- 5. Large span steel bridge members; 6. Ship, machinery manufacturing frame structure.
b). the technical rationality of rolling I-beam: I-beam in industrial and civil buildings, not only saves labor, reduces costs, but also reduces the amount of steel. For example, the steel consumption of hot-rolled I-beam for workshop steel structure can be reduced by 15%-20% compared with hot-rolled wide flange I-beam.
I-beam is used in construction and vehicle manufacturing. Most of the metal columns and beams/roof frame structures in construction are made of A3F low carbon steel, A5, 16Mn, 15MnV steel are also available. The dimensions are height x side width x thickness. For example, A3F100x68 .x4.5 mm.
Calculation formula of theoretical weight of I-beam
|Name||Calculation formula||Symbolic meaning||Calculation example|
T=average leg thickness.
|250mm × 118mm × Weight per m of 10mm I-beam. From the metallurgical product catalog, it is found that t is 13, R is 10, and r is 5, then the weight per m=0.00785 × [250 × 10+2 × 13(118-10)+0.615 × (10 × 10-5 × 5)]|
Shape, length, weight, grade, chemical composition, mechanical properties, technological properties and surface quality of I-beam
Dimension, shape, weight and allowable deviation of hot rolled I-beam
Curvature: the bending of I-beam per meter shall not be greater than 2MM, and the total bending shall not be greater than 0.2% of the total length.
General length: model 10-18, general length 5-19M; Models 20-63, usually 6-19 M.
The I-beam shall be delivered according to the theoretical weight or actual weight.
|I-beam model||Size（mm）||Cross-sectional area（cm2）||Weight （kg/m）|
|High||Leg Width||Abdominal Thickness|
The difference between I-beam and H-beam
People often ask how to choose between I-beam and H-beam, which are similar in shape, in practical use. Many people who have been engaged in the construction industry for many years are unable to explain in detail.
Here is a detailed answer for you: Many people think that I-beam is the domestic name and H-beam is the foreign name, in fact, this cognition is wrong, H-beam and I-beam are different in shape, see the following chart.
At first glance, H-beam and I-beam look very similar, but there are some key differences between the two types of steel beams, which must be understood.
H-beam VS I-beam: The difference in cross-section
As the name implies, H-beam is an H-shaped structural member made of rolled steel and is called a wide wing beam.
It is one of the most used structural members. It looks like an “H” in cross-section, is very strong, and has a larger surface area in the cross-section of the beam.
On the other hand, an I-beam is also known as an H-beam, but it looks like an “I” in cross-section. It is basically a rolled steel beam or a beam with a capital I cross section.
I-section beams have a narrow cross section suitable for direct loads and tensile stresses, but are less resistant to torsion.
Whether the I-beam is ordinary or light, due to the relatively high and narrow section size, the inertia moment of the two main axes of the section has a large difference; Therefore, it is not only directly used in the flexural members in the web plane or formed into lattice stress members. In addition, axial compression members or members perpendicular to the web plane and bending should not be used, which makes them have great limitations in the scope of application.
H-shaped steel is an efficient and economical profile. Because of the reasonable section shape, they can make the steel better play its role and thus improve the bearing capacity. Unlike ordinary I-shaped steel, the flange of H-shaped steel is widened, and the inner and outer surfaces are usually parallel, which makes it easier to connect other components with high-strength bolts; The size composition series is reasonable, and the models are complete, which is convenient for design and selection.
In contrast, H-section beams have a wider cross section than I-section beams and can handle direct loads and tensile stresses and resist torsion.
H-Beam VS I-Beam: The Difference in Flanges
For design purposes, H-beams have longer, wider and heavier flanges than I-beams, but the terms H-beam VS I-beam are used interchangeably in most cases and are commonly referred to as stacked steel beams (RSJ). The horizontal members at the top and bottom of the beam are called flanges, which are usually narrower than I-beams, but almost the same width.
The height of the beam is the web, and H-beams have thicker webs, which makes them relatively stronger than I-beams. On the other hand, single beams have thin webs and tapered flanges.
H-beam and B-beam: Strength Comparison
Made of economical steel, H-beam has a more optimized cross-sectional distribution area and a reasonable strength-to-weight ratio, which means it can provide higher strength per unit weight.
This makes welding of H-shaped beams relatively easier than that of I-shaped beams. It is considered to have a higher strength rate due to the larger surface area in its cross-section.
However, I-beams are usually deeper than they are wide, which makes them well suited to support loads under local buckling. In addition, I-beams are lighter than H-beams, which means they will not be able to withstand as much force as H-beams.
Due to the more optimized cross-sectional area and excellent strength-to-weight ratio, H-beams have higher strength per unit weight.
Typically, I-section beams are deeper than they are wide, so they are particularly well suited to carry loads in local buckling situations. In addition, they are lighter than H-beams, so they will not carry as large a load as H-beams.
H-beam VS I-beam: Application Comparison
H-beams are ideal for mezzanines, decks, bridges and other common residential and commercial construction because of their thicker walls and flanges.
Wide flanges are commonly used in residential projects. the internal dimensions of H-beams are constant to make them the material of choice in trailer and truck structures.
I-beams have a high flange resistance and are the preferred form for structural steel buildings, bridges and other civil engineering projects.
In addition to commercial and residential construction projects, they are used in the manufacture of tracks, elevators, trailer and truck bases, winch and elevator structures and support columns.
H-Beams VS I-Beams: Weight Comparison
An H-beam is usually much heavier than an I-beam, which means it can receive more.
In some buildings where the weight and strength of the wall may represent a structural problem, an I-beam may be better because it is usually lighter.
H-beams are heavier than I-beams.
H-Beam VS I-Beam: Center web comparison
H-beams have a thicker center web, which means they are usually stronger.
An I-beam usually has a thinner center web, which means it cannot usually be stressed as well as an H-beam.
H-beams have a significantly thicker web than I-beams.
H-beam VS I-beam: Fabrication
I-beams are always manufactured as a single unit, while H-beams consist of three metal plates welded together.
H-section beams can be fabricated to any desired size, while the capacity of milling machines limits the production of I-section beams.
An H-section beam is similar to a single metal piece, but it has a beveled surface with three metal plates welded together.
H-beam VS I-beam: Use of span
Due to manufacturing limitations, I-section beams can be used for spans from 33 to 100 feet, while H-section beams can be used for spans up to 330 feet.
H-beam VS I-beam: Difference in Flanges
H-Beams: The top and bottom flanges of H-Beams extend farther out from the web than the flanges of I-Beams.
I-Beams: I-Beams have top and bottom flanges, they are shorter and not as wide as H-Beams.
H-beam flanges are of equal thickness and parallel to each other, while I-beams have tapered flanges with an inclination of 1:10 for better load carrying capacity.
H-beam VS I-beam: distance from the flange end to the center of the web
In I-beam sections, the distance from the flange end to the center of the web is smaller, while in H-beam sections, for similar sections of I-beams, the distance from the flange end to the center of the web is larger.
H-section beam VS I-section beam: rigidity
Usually, H-section beams are more rigid than I-section beams and can carry heavier loads.
H-beam VS I-beam: Welding Performance
H-beam is easier to weld than I-beam due to its straight outer flange. H-beam section is stronger than I-beam section; therefore it can carry more load.
H-beam VS I-beam: Moment of Inertia
The moment of inertia of a beam determines its bending resistance. The higher it is, the less the beam will bend.
H-section beams have wider flanges, higher lateral stiffness and greater moment of inertia than I-section beams, and they are more resistant to bending than I-section beams.
H-section beams VS I-section beams: mechanical properties
H-section beams are a more economical cross-section than I-section beams and have better mechanical properties.
Which is stronger, H-beams or I-beams?
- 1. I-beam whether ordinary or light, because the cross-sectional size are relatively high, narrow, so the difference between the moment of inertia of the two main axes of the cross-section is large, therefore, generally only directly used in its web plane bending members or will be composed of lattice type stress members. For axial compression members or in the perpendicular to the web plane and bending members are not suitable, which makes its application range has great limitations.
- 2. H-shaped steel is a highly efficient economic cross-sectional sections (other cold-formed thin-walled sections, compression steel plates, etc.), due to the reasonable shape of the cross-section, they can make the steel higher performance, improve the ability to cut. Unlike ordinary I-beams, the flange of H-beams is widened, and the inner and outer surfaces are usually parallel, so that they can be easily connected with other members by high-strength bolts. Its size constitutes a reasonable series, and the model is complete, so it is easy to design and choose (except for the I-beam for crane beam).
- 3. The flange of H-beam is of equal thickness, and there are rolled sections and combined sections composed of 3 plates welded together. H-beam rolling is different from ordinary I-beam rolling with only one set of horizontal rolls, because of its wide flange and no slope (or slope is very small), so an additional set of vertical rolls must be rolled at the same time, therefore, the rolling process and equipment are more complex than ordinary mills. The largest domestic production of rolled H-beam height of 800mm, more than can only be welded combination section.
- 4. the side length of I-beam is small, the height is large, and it can only withstand the force in one direction.
- 5. H-beams with deep grooves and large thickness can withstand forces in both directions.
- 6. With the development of steel structure building needs, only I-beam will not work, but also thicken I-beam, which is easy to be destabilized for load-bearing column.
- 7. I-beam can only be used for crossbeam, while H-beam can be used for structural load-bearing column.
- 8. H-beam is a kind of economic section steel with better mechanical properties in section than I-beam, named because the shape of its section is the same as the English letter “H”. The flange of hot-rolled H-beam is wider than that of I-beam, with high lateral stiffness and high bending resistance. The weight of H-beam is lighter than that of I-beam under the same specification.
- 9. The flange of I-beam is thicker in the web section and thinner outside; the flange of H-beam is equal in section.
- 10. HW refers to wide flange H-beam, for example, HW300x300, which means the cross-section height and width are 300mm; HN is narrow flange H-beam, for example, HN300x150, which means the cross-section height is 300 and width is 150; HM has a flange width between the two, for example, HM300x200. HW, HN and HM are all hot-rolled H-beams. HW, HN, and HM are all cross-sectional types of hot-rolled H-beams. The welded ones can generally be written BH.
- 11. HW is the height and flange width of H-beam are basically equal; it is mainly used for steel core column in reinforced concrete frame structure column, also called strong steel column; it is mainly used for column in steel structure.
- 12. HM is H-beam height and flange width ratio is roughly 1.33-1.75; mainly in steel structure: used as steel frame column, used as frame beam in frame structure bearing dynamic load. For example: equipment platform.
- 13. HN is the ratio of H-beam height and flange width greater than or equal to 2, mainly used in beams; I-beam is used equivalent to HN-beam.
H-beams have a more optimized cross-section than I-beams, giving them a reasonable strength-to-weight ratio, i.e., higher strength per unit area. They have a larger surface area in the cross section and therefore have higher strength.
How to find the right supplier of section steel?
When you are looking for a supplier for section steel, it is important to find the right one. This will help you get the best products and services that will meet your needs.
Before you can find a supplier, you must first decide what kind of section steel you need. The type of section steel is determined by its size and shape. For example, if your project requires a large amount of rectangular bars (i.e., long pieces that are wide but not very tall), then it would be difficult to find a supplier who could provide enough sections in time for your deadline. However, if your project requires smaller-sized rectangular or circular bars, there may be plenty of suppliers who can meet all special requests with no problem.
The next step is deciding how much section steel will be needed—you should also consider how many pieces will be required at one time so that the company can prepare properly for delivery on the specified date and time (if necessary). Finally, once those steps are complete and you’ve found a suitable supplier for your needs, it’s important to get them involved early on so they have enough time to source materials before being asked by another customer.
When you are looking for a section steel supplier, it is important that you find the right company. There are many things to consider when choosing a supplier and below is a list of the most important ones:
- Reputation: A good reputation is always important when selecting your suppliers. The company should have an established presence in the market with their excellent products and services as well as providing great customer service.
- Product quality: When finding the right supplier, it is also essential that they produce high quality section steel products which will last longer than other companies’ products or even those from other manufacturers.
- Delivery time: Another thing to look at before committing to any particular supplier is how long it takes for them to deliver your product after placing an order with them and whether or not there are any delays along the way preventing delivery from happening on schedule.
The quality of the products
The quality of your products is a crucial factor for the success of your company. The customer must trust you and know that your products meet their expectations. If not, they will look elsewhere.
Therefore, it is essential to choose a supplier who can provide the right quality and quantity at a reasonable price.
Your supplier should be able to offer you a good product and services.
A good supplier will have a strong reputation in the market, and they will have a good relationship with their customers. They should also be able to provide you with everything that you need, including design consultations and advice regarding any problems or issues that may come up during production.
Suppliers should also be willing to work closely with your company on any projects that you might have in mind. This way they can help solve any problems which may arise during the process of working together as well as providing other benefits such as training staff members who are new or inexperienced at production methods used by suppliers’ companies themselves so there’s no need for employees from either side feeling overwhelmed from learning how things work together (which happens often enough today).
H-beams are highly efficient and economical cut-face steel (there are other cold-formed thin-walled sections and pressed steel plates, etc.), and because of their reasonable cross-sectional shape, they can perform better and increase their load-bearing capacity. Unlike ordinary I-beams, the flanges of H-beams are widened and the inner and outer surfaces are usually parallel so that they can be connected to other members with high-strength bolts. The size composition is reasonable and the type is complete, so it is easy to design and select.
In structural design, I-beams should be selected according to their mechanical properties, weldability, chemical properties and structural dimensions, etc. to choose a reasonable I-beam for use.