Nickel Alloys Nuts
Nuts are internally threaded fasteners (hex and heavy hex) that mate with bolts and studs. Pressure-bolting nuts are specified to ASTM A194 in grades matched to the bolt: 2H with B7, 8M with B8M, and so on.
Choose a grade below for specifications, composition, sizes and weight charts.
Nickel Alloys nuts by grade
| Grade | Specification | Key characteristic | Typical use |
|---|---|---|---|
| Inconel 600 Nuts | ASTM B166 bar stock | ≥ 72% nickel: immune to chloride SCC | Furnace muffles, retorts and trays |
| Inconel 625 Nuts | ASTM B446 bar stock | High strength without age hardening | Seawater piping and offshore systems |
| Inconel 718 Nuts | ASTM B637 | Age-hardenable: yield strength above 1,000 MPa | Aero-engine discs, shafts and casings |
| Incoloy 800 Nuts | ASTM B408 | Fe-Ni-Cr: bridges stainless and nickel alloys | Heat-exchanger and steam-generator tubing |
| Incoloy 825 Nuts | ASTM B425 | Resistant to sulphuric and phosphoric acids | Sour oil and gas piping and tubulars |
| Monel 400 Nuts | ASTM B164 | Ni-Cu alloy: excellent in seawater and brackish water | HF alkylation units in refineries |
| Monel K-500 Nuts | ASTM B865 | Age-hardenable Ni-Cu alloy | Marine pump and propeller shafts |
| Hastelloy C22 Nuts | ASTM B574 | Resists both oxidising and reducing media | Pharmaceutical and fine-chemical reactors |
| Hastelloy C276 Nuts | ASTM B574 | About 16% Mo, 15.5% Cr, 3.7% W | Chemical reactors and heat exchangers |
How nickel alloys nuts are made, sized and tested
How it's madeHot-forged or cold-formed from bar, heat treated (for hardenable grades), tapped and coated if required.
- Size range
- M6 – M100 and ¼" – 4"; heavy hex to ASME B18.2.2; metric to ISO 4032 / 4033
- Finish
- Plain, zinc, galvanised (tapped oversize), fluoropolymer
Testing & documents
- Proof-load tests
- Hardness tests
- Chemical analysis
- EN 10204 3.1 certificate; 3.2 with third-party inspection
Frequently asked questions
Why use heavy hex nuts on flanges?
Heavy hex nuts are thicker and wider across flats than regular hex nuts, which suits the high preloads and larger wrench bearing surfaces needed in pressure bolting.
Which nickel alloys grades are available as nuts?
Inconel 600, Inconel 625, Inconel 718, Incoloy 800, Incoloy 825, Monel 400, Monel K-500, Hastelloy C22, Hastelloy C276.
Which specifications cover nickel alloys nuts?
ASTM B166, ASTM B446, ASTM B637, ASTM B408, ASTM B425, ASTM B164, ASTM B865, ASTM B574, depending on grade.
Need nickel alloys nuts?
Send grade, size, quantity and destination.