ASTM A194 2HM — Chemical Composition & Mechanical Properties
ASTM A194 2HM is a bolting & nut grades grade for heavy hex nuts. 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 2HM at a glance
| Specification | ASTM A194 2HM |
|---|---|
| Material family | Bolting & nut grades |
| Product form | Heavy hex nuts |
| Also known as | 2HM |
| Document | TG-MG-036 · Rev. 1 · October 2026 |
Typical service
Sour-service nuts for A193 B7M studs
Heat treatment
Quenched & tempered, 620 °C min temper
Chemical composition of ASTM A194 2HM (weight %)
Single values are maximums unless shown as a range or “min”.
Mechanical properties
| Proof load stress | 1035 MPa (150 ksi), heavy hex |
|---|---|
| Hardness | 159–235 HBW (84–99 HRB) |
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 2HM
All equivalents| Standard system | Nearest equivalent grade |
|---|---|
| USA — ASTM / ASME | ASTM A194 2HM · ASME SA-194 2HM |
| Europe — EN designation | C45 |
| Europe — W.Nr | 1.0503 |
| Japan — JIS | S45C |
| China — GB / NB | 45 (GB/T 699) |
| China — old GB designation | 45 |
| India — IS | 45C8 (IS 1570-2) |
| UK — BS (withdrawn) | BS 970 080M46 |
Equivalents are the nearest commonly cited grades. Chemistry, mechanical properties and testing differ between standards — compare them before substituting one for another.
Standards for ASTM A194 2HM
All material standardsFAQ
ASTM A194 2HM: common questions
What is the proof load stress of ASTM A194 2HM nuts?
1035 MPa for heavy hex nuts.
What is the carbon content of ASTM A194 2HM?
0.40 min %.
How is ASTM A194 2HM heat treated?
Quenched & tempered, 620 °C min temper.
What is the Chinese (GB) equivalent of ASTM A194 2HM?
The nearest Chinese equivalent is 45 (GB/T 699), formerly 45. Equivalents are close but not identical — compare chemistry and properties before substituting.
What is the JIS equivalent of ASTM A194 2HM?
The nearest Japanese (JIS) equivalent is S45C.
Does Teshi Group supply ASTM A194 2HM?
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.