Differences between ASTM A501 and ASTM A500:
- Molding process
The molding process is the most obvious and fundamental difference between ASTM A500 and A501.
- ASTM A500: The final forming process is cold forming. The tubes are formed at room temperature, and the cold forming process helps to increase yield and tensile strength in structural applications, especially where strength and dimensional accuracy are required.
- ASTM A501: The final forming process is thermoforming. The tubing is formed at high temperatures, allowing the structural tubing to better withstand impact and deformation, suitable for applications requiring high elasticity and energy absorption capacity.
- Manufacturing process
ASTM A500 and A501 are both standards for seamless and welded carbon structural steel tubing, but the acceptable manufacturing process varies due to the final forming process
- ASTM A500: Manufactured using a cold forming process, which allows the product to have tighter tolerances and a smoother surface, suitable for decorative and architectural uses.
- ASTM A501: Manufactured by thermoforming process, the product has a rougher surface and looser tolerances, but has higher yield and tensile strength.
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Standard |
Acceptable manufacturing process |
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ASTM A500 |
Seamless, electric resistance welding |
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ASTM A501 |
Seamless, furnace butt welding (continuous welding), electric resistance welding, submerged arc welding |
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ASTM A501 allows for a variety of welding techniques and requires pipes to be heat treated to improve material uniformity and mechanical properties.
- Heat treatment
- ASTM A500: Allows the pipe to be stress-relieved or annealed. Grade D pipes should be heat-treated to a minimum of 1100 °F [590 °C] for one hour per inch [25 mm] thickness.
- ASTM A501: Permits the addition of positive heat treatment to tubes with wall thickness greater than 1/2 inch [13 mm].
Mechanical properties comparison
ASTM A501 generally provides higher strength levels because the thermoforming process increases the strength of the steel.
| ASTM A501 Tensile and Impact Requirements | |||||||
| Wall Thickness | GRADE A | GRADE B | GRADE C | ||||
| TENSILE STRENGTH,min | All | 58000psi | 400MPa | 65000psi | 448MPa | 70000psi | 483MPa |
| WT≤25mm | 39000psi | 270MPa | 46000psi | 315MPa | 50000psi | 345MPa | |
| 25mm＜WT≤50mm | 38000psi | 260MPa | 45000psi | 310MPa | 49000psi | 340MPa | |
| YIELD STRENGTH,min | 50mm＜WT≤76mm | 36500psi | 250MPa | 42500psi | 290MPa | 47500psi | 330MPa |
| 76mm＜WT≤100mm | 35000psi | 240MPa | 40000psi | 280MPa | 46000psi | 315MPa | |
| ELONGATION,min | 25% | 24% | 23% | ||||
| ASTM A500 ROUND STRUCTURAL TUBING | |||||
| GRADE | TENSILE STRENGTH | YIELD STRENGTH | ELONGATION | ||
| GR.A | 45000psi | 310MPa | 33000psi | 230MPa | 25% |
| GR.B | 58000psi | 400MPa | 42000psi | 290MPa | 23% |
| GR.C | 62000psi | 425MPa | 46000psi | 315MPa | 21% |
| GR.D | 58000psi | 400MPa | 36000psi | 250MPa | 23% |
| ASTM A500 SHAPED STRUCTURAL TUBING | |||||
| GRADE | TENSILE STRENGTH | YIELD STRENGTH | ELONGATION | ||
| GR.A | 45000psi | 310MPa | 39000psi | 270MPa | 25% |
| GR.B | 58000psi | 400MPa | 46000psi | 315MPa | 23% |
| GR.C | 62000psi | 425MPa | 50000psi | 345MPa | 21% |
| GR.D | 58000psi | 400MPa | 36000psi | 250MPa | 23% |
Chemical composition
ASTM A501 has stricter requirements for carbon, phosphorus, and sulfur to provide better weldability. The slightly higher manganese content in ASTM A501 improves the strength and toughness of the structural tubes.
| ASTM A501 COMPOSITION, % | ||||
| GRADE A | GRADE B,C | |||
| HEAT ANALYSIS | PRODUCT ANALYSIS | HEAT ANALYSIS | PRODUCT ANALYSIS | |
| Carbon(C),max | 0.26 | 0.30 | 0.22 | 0.26 |
| Manganese(Mn),max | no requirement | no requirement | 1.40 | 1.45 |
| Phosphorus(P),max | 0.035 | 0.045 | 0.030 | 0.040 |
| Sulfur(S),max | 0.035 | 0.045 | 0.020 | 0.030 |
| Copper(Cu),min | 0.20 | 0.18 | 0.20 | 0.18 |
| ASTM A500 COMPOSITION, % | ||||
| GRADE A, B , and D | GRADE C | |||
| HEAT ANALYSIS | PRODUCT ANALYSIS | HEAT ANALYSIS | PRODUCT ANALYSIS | |
| Carbon(C),max | 0.26 | 0.30 | 0.23 | 0.27 |
| Manganese(Mn),max | 1.35 | 1.40 | 1.35 | 1.40 |
| Phosphorus(P),max | 0.035 | 0.045 | 0.035 | 0.045 |
| Sulfur(S),max | 0.035 | 0.045 | 0.035 | 0.045 |
| Copper(Cu),min | 0.20 | 0.18 | 0.20 | 0.18 |
Application
Both ASTM A500 and A501 are used in welded, riveted, or bolted structures of Bridges and buildings, as well as for general structural purposes. However, due to differences in chemical composition, mechanical properties, etc., specific uses have different focuses
ASTM A500: Suitable for general building and bridge construction, especially where lighter construction and good stiffness are required.
ASTM A501: Commonly used for large Bridges and building structures that need to carry large loads.
ASTM A500 Application:
- Building structural support: ASTM A500 pipe is widely used in high-rise buildings, long-span Bridges, large-scale industrial plants support and load-bearing structures, providing strong support to ensure the stability and safety of the structure.
- Pipeline engineering: Due to its high strength, corrosion resistance, good seismic performance, the pipe is also widely used in the field of pipeline engineering, can be used as water, gas, steam pipeline material, suitable for urban infrastructure construction, industrial pipeline system and other applications.
- Road and tunnel engineering: In road and tunnel engineering, ASTM A500 pipe is the ideal choice for strengthening roadbed and supporting tunnels, providing reliable load capacity and ensuring the stability and safety of roads and tunnels.
- Other applications: In addition to the above application areas, the pipe is also widely used in agricultural irrigation systems, aquaculture facilities, power line supports, etc., which can perform well in various environments and applications to meet various practical needs.
ASTM A501 Application:
- Structural Uses of Bridges and buildings: The ASTM A501 standard covers black and hot-dip galvanized hot-formed welded and seamless carbon steel square, round, rectangular or specially shaped structural pipes for welded, riveted or bolted construction of Bridges and buildings, as well as general structural uses.
- General structural use: The standard is applicable to pipes and fittings for general structural use to ensure their safety and reliability.
