Stainless steels divide into three groups of steel - austenitic, ferritic and martensitic. Austenitic steel is by far the commonest and offers the greatest scope for use. The steel groups and strength classes are designated by a four-digit sequence of letters and numbers as shown in the following example. DIN EN ISO 3506 governs screws and nuts made from stainless steel.
Example:
A2 - 80
A = austenitic steel
2 = type of alloy within group A
80 = tensile strength of at least 800 N/mm2, cold work hardened
Fig. A:
Tab. 10: Common stainless steels and their chemical composition
|
Material designation |
Material no. |
C % |
Si ≤ % |
Mn ≤ % |
Cr % |
Mo % |
Ni % |
Altri % |
A 2 |
X 5Cr Ni 1810 |
1.4301 |
≤ 0.07 |
1.0 |
2.0 |
17.5 to 19.5 |
- |
8.0 to 10.5 |
- |
X 2 Cr Ni 1811 |
1.4306 |
≤ 0.03 |
1.0 |
2.0 |
18.0 to 20.0 |
- |
10 to 12.0 |
- |
|
X 8 Cr Ni 19/10 |
1.4303 |
≤ 0.07 |
1.0 |
2.0 |
17.0 to 19.0 |
- |
11.0 to 13.0 |
- |
|
A 3 |
X 6 Cr Ni Ti 1811 |
1.4541 |
≤ 0.10 |
1.0 |
2.0 |
17.0 to 19.0 |
- |
9.0 to 12.0 |
Ti ≥ 5 X % C |
A 4 |
X 5 Cr Ni Mo 1712 |
1.4401 |
≤ 0.07 |
1.0 |
2.0 |
16.5 to 18.5 |
2.0 to 2.5 |
10.0 to 13.0 |
- |
X 2 Cr Ni Mo 1712 |
1.4404 |
≤ 0.03 |
1.0 |
2.0 |
16.5 to 18.5 |
2.0 to 2.5 |
10 to 13 |
- |
|
A 5 |
X 6 Cr Ni Mo Ti 1712 |
1.4571 |
≤ 0.10 |
1.0 |
2.0 |
16.5 to 18.5 |
2.0 to 2.5 |
10.5 to 13.5 |
Ti ≥ 5 X % C |