ASTM A194 Grade 2HM Heavy Hex Nuts
ASTM A194 Grade 2HM heavy hex nuts — quenched and tempered carbon steel sharing the Grade 2/2H chemistry row (C 0.40% min, Mn 1.00% max), the hardness-controlled 2H variant used in sour-service (NACE) stud-bolt assemblies with A193 B7M studs. Mechanical rows are not tabulated in the collected sources and are not asserted.
Last updated: 2026-11
Specifications
Grade 2HM is the hardness-controlled member of the Grade 2 family: the same carbon-steel chemistry row the specification prints for 2 and 2H (carbon 0.40% minimum, manganese 1.00% maximum), quenched and tempered — the collected grade table titles it "Quenched & tempered carbon steel hvy hex nut" — with the service role set by its hardness control rather than a higher strength number. In stud-bolt practice it is the nut side of sour-service (NACE) assemblies: the collected pairing table puts A193 B7M studs with 2HM nuts where controlled hardness limits the risk of sulfide stress cracking. The collected sources for this batch tabulate chemistry for the 2/2H/2HM row but no hardness or proof-load rows specific to 2HM — those figures stay fail-closed here rather than being carried over from 2H, because 2HM's controlled-hardness condition is not the same condition as 2H. Request the mill certificate against the size and condition of record at quotation.
| Standard | ASTM A194 — Grade 2HM (heavy hex pattern) |
|---|---|
| Material | Carbon steel, quenched and tempered — hardness-controlled variant of the Grade 2 family |
| Chemistry (2 / 2H / 2HM row) | C 0.40% min, Mn 1.00% max, P 0.04% max, S 0.05% max, Si 0.40% max |
| Service pairing | A193 B7M studs + A194 2HM nuts — sour (NACE) service, controlled hardness |
| Hardness / proof load | Not tabulated in the collected sources for 2HM — the 2H rows do not carry over; confirm per mill certificate against the size and condition of record |
Materials
- Carbon steel (quenched and tempered, hardness-controlled)
Ordering & documentation
Documents
Shipments are backed by Mill Test Certificate (MTC), Dimensional Report, Salt Spray Test Report on request, with full batch traceability from raw material to finished product. Quality management follows the owner-confirmed compliance list: ISO 9001:2015, RoHS, REACH. Exact document sets are confirmed on the order.
Quotation
- The fastener family (ASTM A194 Grade 2HM Heavy Hex Nuts) plus the standard designation from your drawing — DIN / ISO / JIS / ASTM / ANSI, or a drawing for custom parts.
- Size (diameter and length), thread type (metric or inch), property class or grade, and coating or finish.
- Quantity per size and your target delivery date.
- Destination country, and any required documents (for example a mill test certificate) so the quote includes them.
Sample & supply
Minimum order quantity is 10,000 pieces. Stock items run 3–7 days. Quantities or variants outside the standard range are confirmed at quotation.
Storage & shipping
Parts are packed for export and shipped factory-direct to buyers in Europe, Asia, the Americas and the Middle East. Store fasteners dry and protected until installation, and keep coated parts in their packaging until use; specific packing and preservation requirements can be stated on the order and confirmed at quotation.
Frequently asked questions
Can I substitute a Grade 2H nut where the drawing calls 2HM?
Not on your own authority. 2HM carries the same base chemistry as 2H but is specified in a hardness-controlled condition for sour-service (NACE) assemblies — the control exists to limit sulfide stress cracking, and 2H's full-strength hardness band can sit above the ceiling the service allows. Where the specification of record says 2HM, order 2HM with a mill certificate showing the hardness result; substitution is the engineer's call, not the supplier's.
Why does this page not list hardness or proof-load numbers like the 2H page?
Because the collected sources for this batch print chemistry for the 2/2H/2HM row but no hardness or proof-load table rows specific to 2HM — its controlled-hardness condition is a different metallurgical condition from 2H, so the 2H figures are not transferable. Rather than borrow numbers across grades, this page states the gap: confirm hardness and proof load per the mill certificate and the specification of record at quotation.
What is the MOQ and lead time for this nut type?
The minimum order quantity is 10,000 pieces. Stock items ship in 3–7 days; non-stock items are confirmed at quotation. Common diameters in this nut type are widely stocked; confirm the exact schedule against quantity and size mix at quotation.
What should an RFQ for this nut type state?
State the standard designation (for example DIN 985 or DIN 6923), nominal thread size and pitch (metric coarse unless fine pitch is required), material and strength pairing with the mating bolt, finish (plain, zinc, or hot-dip galvanized where compatible), required certificates such as a mill test report per EN 10204 3.1, and quantity per size — plus destination country.
Request a Quote
Get factory-direct pricing from the manufacturer.
What to include in your inquiry
- ✓ Standard and property class (e.g. DIN 912, ISO 4762, class 8.8) — or a drawing for custom parts.
- ✓ Sizes, lengths and thread type (metric or inch).
- ✓ Quantity per size and your target delivery date.
- ✓ Destination country, plus any coating or finish requirement.
- ✓ Any documents you need with the shipment (e.g. mill test certificate) so the quote includes them.
- ✓ Your inquiry goes straight to the factory team by email and gets a reply within 24 hours.
- ✓ Factory-direct pricing
- ✓ Standard and custom specifications
- ✓ Factory-direct export to buyers in Europe, Asia, the Americas and the Middle East
- ✓ Full fastener family support