ASTM F594 Stainless Steel Nuts
The stainless nut specification: the same alloy groups and conditions as F593 bolts, with proof stress from 70 ksi annealed to 120 ksi strain hardened for austenitic grades and 160 ksi for hardened 410.
What F594 stainless nuts is.
ASTM F594 is the companion of F593: it covers hex and heavy hex nuts in the same stainless alloy groups, Group 1 (303, 304, 304L, 305 and related), Group 2 (316, 316L), Group 3 (321, 347), the ferritic 430, the martensitic 410, 416 and 431, and the precipitation-hardening 630. Each group has conditions with a proof stress by size and a hardness range, and the nut marking F594A to F594W identifies them.
We machine F594 nuts in every group and condition from certified bar, including the large, jam, heavy and special sizes, passivated, and can supply them silver plated or lubricated to prevent galling on stainless studs.
Chemical composition.
| Element | 304 | 316 | — |
|---|---|---|---|
| Carbon, max | 0.08 | 0.08 | |
| Manganese, max | 2.00 | 2.00 | |
| Phosphorus, max | 0.045 | 0.045 | |
| Sulfur, max | 0.030 | 0.030 | |
| Silicon, max | 1.00 | 1.00 | |
| Chromium | 18.0–20.0 | 16.0–18.0 | |
| Nickel | 8.0–10.5 | 10.0–14.0 | |
| Molybdenum | — | 2.00–3.00 |
Values per ASTM F594-22 Table 1 (verified against the specification). Confirm the edition called out on your purchase order with our estimating team. All groups are listed in the same table; compositions match F593.
Mechanical properties.
| Alloy group · condition · size | Proof stress, hex nuts (ksi) | Proof stress, heavy hex nuts (ksi) | Rockwell hardness | Marking (Group 1 / 2 / 3) | — |
|---|---|---|---|---|---|
| Austenitic · AF · ¼–1½ | 70 | 76 | B85 max | F594A / E / J | |
| Austenitic · A · ¼–1½ | 75 | 81 | B65–B95 | F594B / F / K | |
| Austenitic · CW1 · ¼–⅝ | 100 | 108 | B95–C35 | F594C / G / L | |
| Austenitic · CW2 · ¾–1½ | 85 | 92 | B80–C35 | F594D / H / M | |
| Austenitic · SH1 · ¼–⅝ | 120 | 130 | C24–C36 | F594A / E / J | |
| Austenitic · SH2 · ¾–1 | 110 | 119 | C20–C32 | F594B / F / K | |
| Austenitic · SH3 · 1⅛–1¼ | 100 | 108 | B95–C30 | F594C / G / L | |
| Austenitic · SH4 · 1⅜–1½ | 85 | 92 | B90–C28 | F594D / H / M | |
| 410, 416 · H · ¼–1½ | 100 | 108 | C20–C30 | F594P | |
| 410, 416 · HT · ¼–1½ | 160 | 173 | C34–C45 | F594R |
Values per ASTM F594-22 Table 2 (verified against the specification). Confirm the edition called out on your purchase order with our estimating team. Groups 1, 2 and 3 share the same values with different markings (A–D, E–H, J–M).
Specifications that apply.
How F594 stainless nuts ships from Houston.
- Hex and heavy hex bolts and cap screws
- Studs and threaded rod
- Nuts and washers to match
- Machined specials to drawing
F594 stainless nuts fasteners we make.
Every item is manufactured to your drawing or standard in F594 stainless nuts, imperial or metric, with an EN 10204 3.1 certificate.
Galling and stainless nuts
A stainless nut on a stainless stud will gall if it is run down dry under load. F594 does not address it, so it is worth specifying: an anti-seize compound, a PTFE-coated stud, a silver-plated nut, or a nut in Nitronic 60 all solve it. Matching a cold-worked stud to an annealed nut, or the other way round, also helps because the two surfaces then work-harden differently.
Testing, certification and marking
- Proof load and hardness per lot
- Marking F594A to F594W and manufacturer's identification
- Certificate of conformance or test report with heat number; EN 10204 3.1 available
- Intergranular corrosion capability per ASTM A262 for the austenitic groups
Recent F594 stainless nuts jobs.
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 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.
ASTM A194 / ASME SA-194ASTM A194 Grade 8 (304 Stainless)
304 stainless heavy hex nut for A193 and A320 B8 studs — solution treated, 80 ksi proof load, corrosion resistant from cryogenic to 1500 °F.