Nuts must be made from steel chemical composition see. The following table, which determines the minimum and maximum content of major chemical elements.
Table according to standard ISO 898 (applies to nuts produced by forming)
| Strength class | Limit figures of the chemical composition | ||||
|---|---|---|---|---|---|
| C Max. | Mn Min. | P Max. | S Max. | ||
| 41), 51), 61) | - | 0,50 | - | 0,060 | 0,150 |
| 8, 9 | 041) | 0,58 | 0,25 | 0,060 | 0,150 |
| 102) | 052) | 0,58 | 0,30 | 0,048 | 0,058 |
| 122) | - | 0,58 | 0,45 | 0,048 | 0,058 |
- If the nuts are made of free-cutting steel (rarely can be made of other steels, depending on the agreement between the customer and supplier), the following maximum allowable rates, P, Pb: S = 0.34%, P = 0, 12%, Pb = 0.35%
- The strength of these classes can be added alloying elements in order to achieve the desiredmechanical properties.