ISO 3506-1 is an international standard that specifies the mechanical properties of corrosion-resistant stainless steel bolts, screws, and nuts. The standard covers fasteners are made from the following types of stainless steel:
Austenitic stainless steels (such as Type 304 and 316)
Martensitic stainless steels (such as Type 410)
Duplex stainless steel (such as Type 2205)
The standard includes requirements for the chemical composition, mechanical properties, surface finish, and markings of the fasteners. It also specifies the conditions for testing the fasteners to determine their properties.
The standard is intended for use in the design and manufacture of fasteners for use in environments where corrosion resistance is required. It is commonly used in the construction, automotive, and chemical industries, among others.
The standard specifies the minimum tensile strength, yield strength, and elongation for each type of stainless steel covered by the standard. It also includes requirements for the fasteners' proof load and minimum breaking torque.
The standard specifies the fasteners' minimum surface roughness and maximum surface defects. It also includes requirements for the appearance and colour of the fasteners and the quality of the coatings, if any, applied to the fasteners.
The standard specifies the markings that must be applied to the fasteners to identify their material and mechanical properties. The markings must be legible and indelible and applied in a location easily visible after installation.
The standard specifies the methods and conditions for testing the fasteners to determine their compliance with the standard's requirements. The tests include tensile testing, hardness testing, and corrosion testing.
The standard is part of a series of standards that covers corrosion-resistant stainless steel fasteners. Other parts of the series include ISO 3506-2, which covers the mechanical properties of corrosion-resistant stainless steel set screws and other internally threaded fasteners, and ISO 3506-3, which covers the mechanical properties of corrosion-resistant stainless steel self-tapping screws and self-drilling screws.
| Steel group | Steel grade | Chemical Composition,a mass fraction,% |
Footnotes | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| c | Si | Mn | p | s | Cr | Mo | Ni | Cu | |||
| Austenitic | A1 | 0.12 | 1 | 65 | 02 | 0,15 to 0,35 | 16 to 19 | 07 | S to 10 | 1,75 to 2,25 | bed |
| A2 | 0.10 | 1 | 2 | 0.05 | 003 | 15 to 20 | -e | 8 to 19 | 4 | fg | |
| A3 | 0.08 | 1 | 2 | 0.045 | 003 | 17 to 19 | -e | 9 to 12 | 1 | h | |
| A4 | 0.08 | 1 | 2 | 0.045 | 003 | 16 to 18,5 | 2 to 3 | 10 to 15 | 4 | gi | |
| AS | 0.08 | 1 | 2 | 0.045 | 003 | 16 to 18,5 | 2 to 3 | 10.5 to 14 | 1 | hi | |
| Martensitic | C1 | 0,09 to 0.15 | 1 | 1 | 0.05 | 003 | 11.5 to 14 | - | 1 | - | i |
| C3 | 0,17to 0.25 | 1 | 1 | 0.04 | 003 | 16 to 18 | - | 1,5 to 2,5 | - | - | |
| C4 | 0,08to 0.15 | 1 | 15 | 0.06 | 0,15 to 0,35 | 12 to 14 | 06 | 1 | - | bi | |
| Ferritic | F1 | 0.12 | 1 | 1 | 0.04 | 003 | 15 to 18 | _j | 1 | - | kl |
| Steel group | Steel grade | Property class |
Tensile strength Rm a min. MPa |
Stress at 0,2 °/o permanent strain Rp0,2a min. MPa |
Elongation after fracture Ab min. mm |
|---|---|---|---|---|---|
| Austenitic | A1,A2, A3,A4, AS |
50 | 500 | 210 | 0,6d |
| 70 | 700 | 450 | 0,4d | ||
| 80 | 800 | 600 | 0,3d |
| Steel group | Steel grade | Property class |
Tensile strength Rma min. MPa |
Stress at 0,2 % permanent strain Rp0,2a min MPa |
Elongation after fracture Ab min. mm |
Hardness | ||
|---|---|---|---|---|---|---|---|---|
| HB | HRC | HV | ||||||
| Martensitic | C1 | 50 | 500 | 250 | 0,2d | 147 O 209 | - | 155 to 220 |
| 70 | 700 | 410 | 0,2d | 209 to 314 | 20 to 34 | 220 to 330 | ||
| 110C | 1 100 | 820 | 0,2d | - | 36 to 45 | 350 to 440 | ||
| C3 | 80 | 800 | 640 | 0,2d | 228 to 323 | 21 to 35 | 240 to 340 | |
| C4 | 50 | 500 | 250 | 0,2d | 147 to 209 | - | 155 to 220 | |
| 70 | 700 | 410 | 0,2d | 209 to 314 | 20 to 34 | 220 to 330 | ||
| Ferritic | F1d | 45 | 450 | 250 | 0,2d | 128 to 209 | - | 135 to 220 |
| 60 | 600 | 410 | 0,2d | 171 to 271 | - | 180 to 285 | ||
