Stainless Steel Screws Bolt and Stud
Stainless Steel Fastener Classification:
- Stainless steel bolts Types: stainless steel hexagon head bolts, stainless steel carriage bolts, stainless steel T-bolts, stainless steel square neck bolts, etc.
- Grade and Materials: The grade of stainless steel bolts is divided into 45, 50, 60, 70, 80, and the materials are mainly austenitic A1, A2, A4, martensitic and ferritic C1, C2, C4.
- Stainless Steel Screw Types: stainless steel hexagon socket screws, stainless steel machine screws, stainless steel self-tapping screws, stainless steel drill tail screws, stainless steel tightening screws, etc.

Common Types of Stainless Steel Bolts
Stainless steel hexagon head bolts with half threads | M1.6 – M39 | DIN931 |
---|---|---|
stainless steel hexagon head bolts with full threads | M1.6 – M52 | DIN933 |
stainless steel carriage bolts with large round heads | M5 – M20 | DIN603 |
stainless steel carriage bolts with semi-circular heads | M6 – M20 | GB12 |
stainless steel T-bolts | M5 – M48 | GB37 |
Stainless Steel Screw Chemical Composition
category | group | Stainless Steel Screw Chemical Composition/% | ||||||||
---|---|---|---|---|---|---|---|---|---|---|
C | Si | Mn | P | S | Cr | Mo | NI | Cu | ||
Austenitic | A1 | 0.12 | 1 | 6.5 | 0.2 | 0.15~0.35 | 16~19 | 0.7 | 5~10 | 1.75~2.25 |
A2 | 0.1 | 1 | 2 | 0.05 | 0.03 | 15~20 | — | 8~19 | 4 | |
A3 | 0.08 | 1 | 2 | 0.045 | 0.03 | 17~19 | — | 9~12 | 1 | |
A4 | 0.08 | 1 | 2 | 0.045 | 0.03 | 16~18.5 | 2~3 | 10~15 | 1 | |
A5 | 0.08 | 1 | 2 | 0.045 | 0.03 | 16~18.5 | 2~3 | 10.5 ~ 14 | 1 | |
Martensite | C1 | 0.09~0.15 | 1 | 1 | 0.05 | 0.03 | 11.5~14 | — | 1 | — |
C3 | 0.17~0.25 | 1 | 1 | 0.04 | 0.03 | 16~18 | — | 1.5~2.5 | — | |
C4 | 0.08~0.15 | 1 | 1.5 | 0.06 | 0.15~0.35 | 12~14 | 0.6 | 1 | — | |
ferrite | F1 | 0.12 | 1 | 1 | 0.04 | 0.03 | 15~ 18 | — | 1 | — |
Stainless Bolt and Screws for Sale

Material: 304、316
Size: M3—M64、3/16”—1-1/2”
Standard: DIN933, DIN931, GB5782, GB5783, GB30, ANSI B18.2.1, JIS B1180

Material: 304、316
Size: ST2.2—ST6.3
Standard: GB845、GB846、GB847、DIN7981、
DIN7982、DIN7983、GB2670.1、
GB2670.2、ISO14585、ISO14586、
JIS B1122、YB845、YB846、YB407
A1-A5 Stainless Steel Fastener Features
The A1 group steel is specially designed for mechanical processing. It has a relatively high sulfur content and lower corrosion resistance than steel with corresponding standard sulfur content. The A2 group steel is the most widely used stainless steel, which can be used in kitchen equipment and chemical equipment. The A3 group steel is a stable stainless steel with the same performance as the A2 group steel. The A4 group steel is acid-resistant steel, containing Mo element, and has good corrosion resistance. The A5 group steel is a stable acid-resistant steel with the same performance as the A4 group steel.
Stainless Steel Screws from AGICO
Our stainless steel screws are mainly made of austenitic stainless steel SUS304 and SUS316. SUS304, also known as A2, is mainly used for the manufacture of ordinary stainless steel bolts, screws, washers, and nuts, with a strength grade of 70 for bolts. SUS316, also known as A4, is mainly used for the manufacture of high-corrosion-resistant stainless steel bolts, screws, washers, and nuts, with a strength grade of 70 for bolts, which can also reach high strength grade 80.
SUS304 and SUS316 stainless steel are generally non-magnetic in normal state. They have slight magnetism after cold working and can maintain their structure without phase change at various temperatures, so they cannot be hardened by heat treatment.
The performance level of stainless steel screws is composed of two numbers, representing its tensile strength divided by 10. The performance level of austenitic steel is 50, 70, 80, for example, the performance level of A2 group steel is represented by A2-50, A2-70, A2-80, etc.
A2-70 means austenitic steel, cold-worked, with a minimum tensile strength of 700N/mm2 or 700MPa.
Type | Group | Strength Level | thread diameter | Tensile strength σb min/Mpa | Specified non-proportional elongation stress σp0.2 min/MPa | Elongation after breaking δ min/mm |
---|---|---|---|---|---|---|
Austenitic | A1、A2、A3、A4、A5 | 50 | ≤M39 | 500 | 210 | 0.6d |
70 | ≤M24 | 700 | 450 | 04d | ||
80 | ≤M24 | 800 | 600 | 0.3d |