The ASTM F594 standard specifies the criteria for stainless steel square and hex nuts with nominal diameters ranging from 1/4" to 1 1/2 inch, in a variety of alloys commonly used and intended for service applications needing general corrosion resistance. Ten austenitic stainless steel alloys, two ferritic stainless steel alloys, four martensitic stainless steel alloys, and one precipitation hardening stainless steel alloy are covered. Specification ASTM F593 covers suitable bolts, hex cap screws, and studs for use with nuts in this specification. All bolts, hex cap screws, and studs used with these nuts must meet the standards of ASTM F593 and be of the same alloy group, unless otherwise indicated.
| Alloy Group | UNS Designation | Alloy | C | Mn | P | S | Si | Cr | Ni | Cu | Mo | Others |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ASTM F594 Alloy Group4 | S43000 | 430 | 0.12 | 1 | 0.04 | 0.030 | 1 | 16.0 to 18.0 | . . . | . . . | 0.60 maxA | . . . |
| Stainless Alloy Group | ConditionB | Alloy Mechanical Property Marking | Nominal Diam- eter, in. | Proof Stress, Hex Nuts ksi, min | Proof Stress, Heavy Hex Nuts ksi, minC | Rockwell Hardness |
|---|---|---|---|---|---|---|
| ASTM F594 Alloy Group 4 (430) |
A | F594N | 1/4 to 11/2 , incl | 55 | 59 | 85 max |
| CW1 | F594V | 1/4 to 5/8 , incl | 60 | 65 | B75 to 98, incl | |
| CW2 | F594W | 3/4 to 11/2 , incl | 55 | 59 | B65 to 95, incl |