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Eastern Steel Manufacturing Co.,Ltd is a leading manufacturer and distributor of seamless steel pipe, welded steel pipe, OCTG products and fittings. We supply first-step processing, semi-finished parts and finished parts to help our clients meet fabrication requirements beyond their capacity or to improve operations by moving forward the pre-production processing.
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In this column you can find the steel pipe related articles you need, including industry trends, product standards and materials, and some technical guidelines.
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Eastern Steel Manufacturing Co.,Ltd not only improve product production and sales services, but also provide additional value-added services. As long as you need, we can complete your specific needs together.
Projects
Many years of large-scale project experience in various fields（Oil & Gas, Construction, Power Energy, Marine & Offshore, Water Treatment, Exploration & Drilling Services, Pipeline & Petrochemical etc.）, professional project team is responsible from receiving until the end of the project.
RHS steel (Rectangular tube) is a type of hollow, long steel tube, also known as flat tube, flat square tube, or square-flat tube. With the same bending and torsional strength, rectangular tubes are lighter, making them widely used in the manufacture of mechanical parts and engineering structures.
ASTM A500 is a standard developed by ASTM International, covering cold-formed welded and seamless carbon steel structural tubes.
ASTM A500 rectangular tube specifically refers to hollow structural steel profiles with rectangular cross-sections conforming to this standard. ASTM A500 Class B rectangular tubes are the most commonly used and widely adopted standard rectangular hollow structural steel profiles in the construction and structural engineering fields in North America and internationally.
Excellent weldability;
Good machinability;
Cold working capability;
Aesthetically pleasing.
A500 carbon steel structural tubes are manufactured using only materials conforming to carbon steel standards. The chemical composition of A500 is primarily iron, with added carbon, manganese, phosphorus, sulfur, and copper.
Long side: 2 inches to 20 inches or longer.
Wall thickness: 0.125 inches to 0.5 inches or thicker.
The ASTM A500 standard includes four grades: A, B, C, and D. Each grade has different strength requirements.
Grades B and C are the most commonly used grades for rectangular tubes.
The minimum yield strength for grade B is 46,000 psi.
Grade C has a higher yield strength of 50,000 psi.
These grades ensure that the tubing can withstand loads, pressure, and resist deformation during use.
The excellent mechanical properties of ASTM A500 rectangular tubing make it ideal for both static and dynamic structures.
|
Element |
Grades A, B and D |
Grace C |
||
|
Heat |
Product |
Heat |
Product |
|
|
Carbon, max |
0.26 |
0.30 |
0.23 |
0.27 |
|
Manganese, max |
... |
... |
1.35 |
1.40 |
|
Phosphorus, max |
0.035 |
0.045 |
0.035 |
0.045 |
|
Sulfur, max |
0.035 |
0.045 |
0.035 |
0.045 |
|
Copper, when copper steel is specified, min |
0.20 |
0.18 |
0.20 |
0.18 |
|
|
Grade A |
Grade B |
Grade C |
Grade D |
|
Tensile strength, mn, ps (MPa) |
45 000 |
58 000 |
62 00 |
58 000 |
|
Yield strength, mn, psi (MPa) |
39 000 |
46 000 |
50 000 |
36 000 |
|
Elongation in 2 in. (50.8 mm), min, %A |
25B |
23C |
21D |
23C |
There are multiple considerations that must be accounted for when determining the outside dimensional tolerances for RHS steel. The chart below and the following attributes describes the exact outside dimensional tolerances for A500 carbon steel.
|
Outside Large Flat Dimension, in. (mm) |
Large Flat Dimension Tolerance, A plus and minus, in. (mm) |
|
2½ (63.5) or under |
0.020 (0.51) |
|
Over 2½ to 3½ (63.5 to 88.9), incl |
0.025 (0.64) |
|
Over 3½ to 5½, inc |
0.030 (0.76) |
|
Over 5½ (139.7) |
0.01 times large flat dimension |
|
Specified Dimension of Longest Side, in. (mm) |
Maximum Twist in the First 3 ft (1 m) and in each additional 3 ft |
|
|
|
in. |
mm |
|
1½ (38.1) and under |
0.050 |
1.39 |
|
Over 1½ to 2½ (38.1 to 63.5),incl |
0.062 |
1.72 |
|
Over 2½ to 4 (63.5 to 101.6), incl |
0.075 |
2.09 |
|
Over 4 to 6 (101.6 to 152.4), incl |
0.087 |
2.42 |
|
Over 6 to 8 (152.4 to 203.2), incl |
0.100 |
2.78 |
|
Over 8 (203) |
0.112 |
3.11 |
ASTM A500 is often compared to the following standards:
ASTM A513: Used for mechanical tubing, not structural tubing.
ASTM A36: Used for structural profiles such as I-beams, not tubing.
EN 10210: European standard for thermoformed structural tubing.
In North America, ASTM A500 remains the preferred standard for welded and seamless structural tubing.
ASTM A500 rectangular tubing is used in numerous industries due to its high strength, good formability, and wide range of applications:
It is commonly found in commercial buildings, warehouses, and residential buildings. Its hollow structure effectively reduces weight while maintaining structural performance.
RHS steel is used in bridges, road signs, guardrails, and urban railings. Its reliability under dynamic stress is critical for safety.
This tubing is ideal for manufacturing frames for equipment, agricultural machinery, and transportation systems.
Modern furniture manufacturers use ASTM A500 tubing for both aesthetic and practical considerations. Its clean lines and strength make it ideal for industrial design.
RHS steel is very strong. Due to its unique shape, rectangular tubing distributes stress evenly when subjected to external forces, thus improving its overall strength.
Compared to traditional CHS steel, RHS steel has a more stable cross-sectional shape, effectively resisting external pressure and bending forces.
RHS steel, due to its rectangular shape, is generally stronger than square tubes (SHS steel).
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