The ASTM F594 standard provides the requirements for stainless steel square and hex nuts with nominal diameters ranging from 1/4" to 1 1/2" in a variety of alloys routinely used and intended for general corrosion resistance in service applications. The book covers ten austenitic stainless steel alloys, two ferritic stainless steel alloys, four martensitic stainless steel alloys, and one precipitation-hardening stainless steel alloy. The ASTM F593 specification provides appropriate bolts, hex cap screws, and studs for use with nuts. Unless otherwise specified, all bolts, hex cap screws, and studs used with these nuts must conform to ASTM F593 specifications and be of the same alloy group.
| Alloy Group | UNS Designation | Alloy | C | Mn | P | S | Si | Cr | Ni | Cu | Mo | Others |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ASTM F594 Alloy Group 7 | S17400 | 630 | 0.07 | 1.00 | 0.040 | 0.030 | 1.00 | 15.0 to 17.5 | 3.0 to 5.0 | 3.0 to 5.0 | . . . | Cb+Ta 0.15-0.45 |
| 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 7 (630) |
AH | F594U | 1/4 to 11/2 , incl | 135 | 146 | C28 to 38, incl |