ASTM A511 — Seamless stainless steel mechanical tube
Grades
TP304, TP304L, TP316, TP316L, TP321, TP347, 410, 416, 420, 430, 440A, 440B, 440C
Chemical composition and mechanical properties
| Grade | Chemical composition | Mechanical properties |
|---|---|---|
| TP304 | C≤0.08, Si≤0.75, Mn≤2.00, P≤0.045, S≤0.030, N≤0.10, Cr 18.00-20.00, Ni 8.00-11.00 | Rm ≥515 MPa, Rp0.2 ≥205 MPa, A≥40%, HB≤201, austenitic 304 |
| TP304L | C≤0.030, Si≤0.75, Mn≤2.00, P≤0.045, S≤0.030, N≤0.10, Cr 18.00-20.00, Ni 8.00-12.00 | Rm ≥485 MPa, Rp0.2 ≥170 MPa, A≥40%, HB≤201, austenitic ultra-low carbon 304L |
| TP316 | C≤0.08, Si≤0.75, Mn≤2.00, P≤0.045, S≤0.030, N≤0.10, Cr 16.00-18.00, Ni 10.00-14.00, Mo 2.00-3.00 | Rm ≥515 MPa, Rp0.2 ≥205 MPa, A≥40%, HB≤217, austenitic with Mo 316 |
Application scope
ASTM A511 specifies seamless stainless steel tubing for mechanical structures, covering grades with austenitic, ferritic, and martensitic microstructures. Austenitic grades offer good corrosion resistance and toughness, while martensitic grades can be heat-treated to improve strength and wear resistance. The standard emphasizes dimensional accuracy, mechanical properties, and machinability, making it suitable for manufacturing structural and transmission components requiring cutting, boring, or further machining.
Typical applications
Widely used as tube blanks for mechanical structural parts, hydraulic cylinder barrels and sleeves, bearing sleeves, and various rotating parts, it is also used for machining automotive parts, pump and valve housings, and precision instrument components. Austenitic varieties are suitable for parts with high corrosion resistance requirements, while martensitic varieties, after quenching and tempering, are used for wear-resistant bushings and pin sleeves. Its excellent machinability meets the requirements for manufacturing high-precision and load-bearing parts.
