ASTM A-193 CHEMICAL COMPOSITION
Extremely common in the industrial piping world, this specification covers alloy and stainless steel bolting material for pressure vessels, valves, flanges, and fittings for high-temperature service. The term bolting material as used in this specification covers bars, bolts, screws, studs, stud bolts, and wire. Bars and wire shall be hot-wrought. The material may be further processed by center less grinding or by cold drawing. Austenitic stainless steel may be carbide solution treated or carbide solution treated and strain-hardened.
Several grades are covered, including ferritic steels and austenitic stainless steels designated B5, B8, and so forth. Selection will depend upon design, service conditions, mechanical properties, and high-temperature characteristics.
| Type | Ferritic Steels | ASTM-193 CHEMICAL COMPOSITION | ||||||
Identification | B5 | B6 and B6X – S41000 | ||||||
| Grade | 5% Chromium (Type 501) | 12% Chromium (Type 410) | ||||||
| Element | Range | Tolerance +/- | Range | Tolerance +/- | ||||
| Carbon | .10 min | 0.01 under | 0.15 max | 0.01 over | ||||
| Manganese, max | 1.00 | 0.03 under | 1.00 | 0.03 over | ||||
| Phosphorus, max | 0.040 | 0.005 over | 0.040 | 0.005 over | ||||
| Sulfur, max | 0.030 | 0.005 over | 0.03 | 0.005 over | ||||
| Silicon | 1.00 max | 0.05 over | 1.00 max | 0.05 over | ||||
| Chromium | 4.00 – 6.00 | 0.10 | 11.5 – 13.50 | 0.15 | ||||
| Molybdenum | 0.40 – 0.65 | 0.05 | – | – | ||||
| Type | Ferritic Steels | |||||||
Identification | B7, B7M | B16 | ||||||
| Grade | Chromium – Molybdenum (C4140,4142,4145,4140 H, 4142 H, 4145H) | Chromium – Molybdenum – Vanadium | ||||||
| Element | Range | Tolerance +/- | Range | Tolerance +/- | ||||
| Carbon | 0.37 – 0.49 | 0.02 | 0.36 – 0.44 | 0.02 | ||||
| Manganese | 0.65 – 1.10 | 0.04 | 0.45 – 0.70 | 0.03 | ||||
| Phosphorus, max | 0.035 | 0.005 over | 0.035 | 0.005 over | ||||
| Sulfur, max | 0.040 | 0.005 over | 0.040 | 0.005 over | ||||
| Silicon | 0.15 – 0.35 | 0.02 | 0.15 – 0.35 | 0.02 | ||||
| Chromium | 0.75 – 1.20 | 0.05 | 0.8 – 1.15 | 0.05 | ||||
| Molybdenum | 0.15 – 0.25 | 0.02 | 0.50 – 0.65 | 0.03 | ||||
| Vanadium | – | – | 0.25 – 0.35 | 0.03 | ||||
| Aluminum, max% | – | – | 0.015 | – | ||||
| Type | Austentic Steels, Class 1, 1A, 1D, and 2 | |||||||
Identification | B8, B8A | B8C, B8CA | B8M, B8MA, B8M2, B8M3 | B8P, B8PA | ||||
| Grade | Unstabilized 18 chromium – 8 Nickel (Type 304 Stainless) | Stabilized 18 Chromium- 8 Nickel (Type 347 Stainless) | 18 Chromium- 10 Nickel- 2 Molybdenum (Type 316 Stainless) | Unstabilized 18 Chromium – 8 Nickel (Type 305 Nickel) | ||||
| Element | Range | Tolerance +/- | Range | Tolerance +/- | Range | Tolerance +/- | Range | Tolerance +/- |
| Carbon, max | 0.08 | 0.01 over | 0.08 | 0.01 over | 0.08 | 0.01 over | 0.12 | 0.01 over |
| Manganese, max | 2.00 | 0.04 over | 2.00 | 0.04 over | 2.00 | 0.04 over | 2.00 | 0.04 over |
| Phosphorus, max | 0.045 | 0.010 over | 0.045 | 0.010 over | 0.045 | 0.010 over | 0.045 | 0.010 over |
| Sulfur, max | 0.030 | 0.005 over | 0.030 | 0.005 over | 0.030 | 0.005 over | 0.030 | 0.005 over |
| Silicon | 1.00 | 0.05 over | 1.00 | 0.05 over | 1.00 | 0.05 over | 1.00 | 0.05 over |
| Chromium | 18.00 – 20.00 | 0.20 | 17.00 – 19.00 | 0.20 | 16.00 – 18.00 | 0.20 | 17.00 – 19.00 | .20 |
| Nickel | 8.00 – 10.50 | 0.15 | 9.00 – 13.00 | 0.15 | 10.00 – 14.00 | 0.15 | 11.00 – 13.00 | 0.15 |
| Molybdenum | – | 2.00 – 3.00 | 0.10 | – | – | |||
| Columbium + Tantalum | – | 10x carbon, min | 0.05 under | |||||
| Type | Austentic Steels, Classes 1A, 1B, 1D and 2 | |||||||
Identification | B8N, B8NA | B8MN, B8MNA | B8MLCuN, B8MLCuNa | |||||
| Grade | (TYPE 304N) s 30451 | (TYPE 316N) s 31651 | S 31254 | |||||
| Element | Range | Tolerance +/- | Range | Tolerance +/- | Range | |||
| Carbon, max | 0.08 | 0.01 over | 0.08 | 0.01 over | 0.020 | |||
| Manganese, max | 2.00 | 0.04 over | 2.00 | 0.04 over | 1.00 | |||
| Phosphorus, max | 0.045 | 0.010 over | 0.045 | 0.010 over | 0.030 | |||
| Sulfur, max | 0.030 | 0.005 over | 0.030 | 0.005 over | 0.010 | |||
| Silicon, max | 1.00 | 0.05 over | 1.00 | 0.05 over | 0.80 | |||
| Chromium | 18.00 – 20.00 | 0.20 | 16.00 – 18.00 | 0.20 | 19.5 – 20.5 | |||
| Nickel | 8.00 – 10.50 | 0.15 | 10.00 – 14.00 | 0.15 | 17.5 18.5 | |||
| Molybdenum | – | – | 2.00 – 3.00 | 0.10 | 6.0 6.5 | |||
| Nitrogen | 0.10 – 0.16 | 0.01 | 0.10 – 0.16 | 0.01 | 0.18 – 0.22 | |||
| Copper | – | – | – | – | 0.50 – 1.00 | |||
| Type | Austentic Steels, Classes 1, 1A, and2 | |||||||
Identification | B8T, B8TA | |||||||
| Grade | Stabilized 18 Chromium – 8 Nickel (Type 321) | |||||||
| Element | Range | Tolerance +/- | ||||||
| Carbon, max | 0.08 | 0.01 over | ||||||
| Manganese, max | 2.00 | 0.04 over | ||||||
| Phosphorus, max | 0.045 | 0.010 over | ||||||
| Sulfur, max | 0.030 | 0.005 over | ||||||
| Silicon, max | 1.00 | 0.05 | ||||||
| Nickel | 9.00 – 12.00 | 0.15 | ||||||
| Chromium | 17.00 – 19.00 | 0.20 | ||||||
| Titanium | 5 X CARBON, MIN | 0.05 under | ||||||
| Type | Austentic Steels, Classes 1C and 1D | |||||||
Identification | B8R, B8RA | B8S, B8SA | ||||||
| Grade | 22 Chromium – 13 Nickel – 5 Manganese | 18 Chromium – 8 Nickel – 4 Silicon + Nitrogen | ||||||
| Element | Range | Tolerance +/- | Range | Tolerance +/- | ||||
| Carbon, max | 0.06 | 0.01 over | 0.10 | 0.01 over | ||||
| Manganese, max | 4.00 – 6.00 | 0.05 | 7.00 – 9.00 | 0.06 | ||||
| Phosphorus, max | 0.040 | 0.005 over | 0.040 | 0.005 over | ||||
| Sulfur, max | 0.030 | 0.005 over | 0.030 | 0.005 over | ||||
| Silicon | 1.00 MAX | 0.05 over | 3.5 – 4.5 | 0.15 | ||||
| Chromium | 20.50 – 23.50 | 0.25 | 16.00 – 18.00 | 0.20 | ||||
| Nickel | 11.50 – 13.50 | 0.15 | 8.00 – 9.00 | 0.10 | ||||
| Molybdenum | 1.50 – 3.00 | 0.10 | – | – | ||||
| Nitrogen | 0.20 – 0.40 | 0.02 | 0.08 – 0.18 | 0.01 | ||||
| Columbium + Tantalum | 0.10 – 0.30 | 0.05 | – | – | ||||
| Vanadium | 0.10 – 0.30 | 0.02 | – | – | ||||
| Type | Austentic Steels, Classes 1, 1A, and 1D | |||||||
| Identification | B8LN, B8LNA | B8MLN, B8MLNA | ||||||
| Grade | TYPE 304N WITH RESTRICTED CARBON | TYPE 316N WITH RESTRICTED CARBON | ||||||
| Element | Range | Tolerance +/- | Range | Tolerance +/- | ||||
| Carbon, max | 0.030 | 0.005 over | 0.030 | 0.005 over | ||||
| Manganese, max | 2.00 | 0.04 over | 2.00 | 0.04 over | ||||
| Phosphorus, max | 0.045 | 0.010 over | 0.045 | 0.010 over | ||||
| Sulfur, max | 0.030 | 0.005 over | 0.030 | 0.005 over | ||||
| Silicon | 1.00 | 0.05 over | 1.00 | 0.05 over | ||||
| Chromium | 18.00 – 20.00 | 0.20 | 16.00 – 18.00 | 0.20 | ||||
| Nickel | 8.00 – 10.50 | 0.15 | 10.00 – 14.00 | 0.15 | ||||
| Molybdenum | – | – | 2.00 – 3.00 | .10 | ||||
| Nitrogen | 0.10 – 0.16 | 0.01 | 0.10 – 0.16 | 0.01 | ||||
