ASTM A194 8 — Chemical Composition & Mechanical Properties
ASTM A194 8 is a bolting & nut grades grade for heavy hex nuts (UNS S30400, EN / W.Nr 1.4301). It is also known as 304. This sheet summarises its chemical composition limits, minimum mechanical properties, heat treatment and typical service. Teshi Group manufactures stud bolts and nuts in this grade.
ASTM A194 8 at a glance
| Specification | ASTM A194 8 |
|---|---|
| Material family | Bolting & nut grades |
| Product form | Heavy hex nuts |
| UNS number | S30400 |
| EN / W.Nr equivalent | 1.4301 |
| Also known as | 304 |
| Document | TG-MG-037 · Rev. 1 · October 2026 |
Typical service
Nuts for A193 B8 studs
Heat treatment
Carbide solution treated
Chemical composition of ASTM A194 8 (weight %)
Single values are maximums unless shown as a range or “min”.
Mechanical properties
| Proof load stress | 550 MPa (80 ksi), heavy hex |
|---|---|
| Hardness | 126–300 HBW |
About bolting & nut grades
Flange bolting is specified as a stud-bolt grade plus a nut grade. ASTM A193 covers high-temperature bolting (B7, B7M, B16, B8, B8M), A320 covers low-temperature bolting (L7, L7M, L43, B8 classes), A453 covers high-strength austenitic bolting (Grade 660), and A194 covers the nuts (2H, 2HM, 4, 7, 8, 8M).
Reference information compiled from the published standard for convenience. It does not replace the current edition of the governing standard, which takes precedence. Verify critical dimensions and properties before design, purchase or fabrication. Teshi Engineers & Sales Promoters (P) Ltd accepts no liability for errors or omissions.
International equivalents of ASTM A194 8
All equivalents| Standard system | Nearest equivalent grade |
|---|---|
| USA — ASTM / ASME | ASTM A194 8 · ASME SA-194 8 |
| USA — UNS | S30400 |
| Europe — EN designation | X5CrNi18-10 |
| Europe — W.Nr | 1.4301 |
| Japan — JIS | SUS304 / SUSF304 |
| China — GB / NB | S30408 (06Cr19Ni10) |
| China — old GB designation | 0Cr18Ni9 |
| India — IS | X04Cr19Ni9 (IS 6911) |
| UK — BS (withdrawn) | 304S31 |
Equivalents are the nearest commonly cited grades. Chemistry, mechanical properties and testing differ between standards — compare them before substituting one for another.
Same alloy in other product forms
| Product form | Specification / grade |
|---|---|
| Forged flanges & fittings | ASTM A182 F304 |
| Seamless pipe (seamless & welded) | ASTM A312 TP304 |
| Wrought butt-weld fittings | ASTM A403 WP304 |
| Stud bolts / bolting | ASTM A193 B8 Cl.1 |
FAQ
ASTM A194 8: common questions
What is the proof load stress of ASTM A194 8 nuts?
550 MPa for heavy hex nuts.
What is the carbon content of ASTM A194 8?
0.08 max %.
What is the UNS number and EN equivalent of ASTM A194 8?
UNS S30400; the nearest European designation is W.Nr 1.4301. Equivalents are close but not identical — check the specification if substituting.
How is ASTM A194 8 heat treated?
Carbide solution treated.
What is the Chinese (GB) equivalent of ASTM A194 8?
The nearest Chinese equivalent is S30408 (06Cr19Ni10), formerly 0Cr18Ni9. Equivalents are close but not identical — compare chemistry and properties before substituting.
What is the JIS equivalent of ASTM A194 8?
The nearest Japanese (JIS) equivalent is SUS304 / SUSF304.
Does Teshi Group supply ASTM A194 8?
Teshi Group manufactures stud bolts and nuts in this grade. Send your size, rating and quantity to info@teshigroup.com for a quotation with EN 10204 3.1 certificates.
Related products, data sheets and standards
Ready to build to spec?
Share your drawing, bill of materials or technical requirements with the Teshi team.