302 Stainless Steel (UNS S30200)
The original 18-8, with carbon to 0.15 percent for a little more strength in cold-worked springs and formed parts; largely replaced by 304 for fasteners.
What 302 Stainless is.
Type 302 is the parent of the 18-8 family. It carries the same chromium and nickel as 304 but allows carbon up to 0.15 percent, which raises the work-hardening response and made it the traditional spring and formed-wire grade. In bar and fastener form its strength limits are the same as 304, ; it is not listed in ASTM F593, so stainless bolts of this type are ordered as 304 in F593 Alloy Group 1.
Most drawings that call for 302 today are satisfied by 304, and 304 is what we stock. We supply true 302 when a specification requires it, from certified A276 bar, and can machine or cold work it to the F593 condition ordered.
Chemical composition.
| Element | Symbol | Min % | Max % |
|---|---|---|---|
| Carbon | C | — | 0.15 |
| Manganese | Mn | — | 2.00 |
| Phosphorus | P | — | 0.045 |
| Sulfur | S | — | 0.030 |
| Silicon | Si | — | 1.00 |
| Chromium | Cr | 17.0 | 19.0 |
| Nickel | Ni | 8.0 | 10.0 |
| Nitrogen | N | — | 0.10 |
Values per ASTM A276/A276M-17 Tables 1 and 2 (verified against the specification). Confirm the edition called out on your purchase order with our estimating team.
Mechanical properties.
| Condition and nominal diameter (in.) | Tensile strength, min (ksi) | Yield strength 0.2% offset, min (ksi) | Elongation, min (%) | Reduction of area, min (%) | Hardness |
|---|---|---|---|---|---|
| Condition A (annealed), hot finished — all | 75 | 30 | 40 | 50 | — |
| Condition A, cold finished — ½ and under | 90 | 45 | 30 | 40 | — |
| Condition A, cold finished — over ½ | 75 | 30 | 30 | 40 | — |
| Condition B (cold worked) — ¾ and under | 125 | 100 | 12 | 35 | — |
| Condition B — over ¾ to 1 | 115 | 80 | 15 | 35 | — |
| Condition B — over 1 to 1¼ | 105 | 65 | 20 | 35 | — |
| Condition B — over 1¼ to 1½ | 100 | 50 | 24 | 45 | — |
| Condition B — over 1½ to 1¾ | 95 | 45 | 28 | 45 | — |
Values per ASTM A276/A276M-17 Tables 1 and 2 (verified against the specification). Confirm the edition called out on your purchase order with our estimating team. Condition B limits are shared with 304 and 316.
Specifications that apply.
How 302 Stainless ships from Houston.
- Hex and heavy hex bolts and cap screws
- Full-thread studs and threaded rod
- Socket head cap and set screws
- Hex, jam and lock nuts
- Washers and spacers
- Machined components from certified bar
302 Stainless fasteners we make.
Every item is manufactured to your drawing or standard in 302 Stainless, imperial or metric, with an EN 10204 3.1 certificate.
What is 302 stainless steel?
302 was the first of the 18-8 austenitic stainless steels and is chemically close to 304, with a higher carbon limit (0.15 against 0.08 percent), chromium 17 to 19 rather than 18 to 20 percent, nickel 8 to 10 rather than 8 to 11 percent and a 0.10 percent nitrogen limit. Higher carbon makes it work-harden faster, which suited spring wire, and it is still specified for spring pins and formed parts on older drawings. For machined fasteners it behaves like 304 and shares the A276 Condition A and Condition B bar tables, though A276 lists no Condition S for 302 and F593 does not list the grade at all.
302 or 304?
Unless the drawing is explicit, 304 is the practical answer: it is the same family, easier to source, and meets every 302 property in the fastener specifications. Where a customer's approved-material list names 302, we will supply certified 302 bar so the paperwork matches.
Testing, certification and marking
- Tensile and hardness tested per lot on the finished product
- Manufacturer's identification on every piece; bolts supplied to F593 are marked as 304 (F593A to F593D)
- EN 10204 3.1 material test report with heat number and chemistry; 3.2 witness available
- PMI verification and intergranular corrosion testing (ASTM A262) arranged on request
304 Stainless Steel (UNS S30400)
The general-purpose 18-8 stainless: 75 ksi annealed bar, cold-worked bolts to 160 ksi, non-magnetic, and resistant to water, food and most mild chemicals.
ASTM A582 bar · ASTM F593 bolts303 Free-Machining Stainless Steel (UNS S30300)
304 with sulfur added for fast, clean machining — the grade for complex turned fasteners and fittings where corrosion resistance can give a little.
ASTM A276 bar · ASTM F593 bolts316 Stainless Steel (UNS S31600)
The marine and chemical-plant stainless: 2 to 3 percent molybdenum for pitting and crevice resistance in chlorides, with the same strength tables as 304.