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 |
||||
