A2 Stainless Steel Slotted Hex Nuts, UNC combine the dimensional form of ASME B18.2.2 with the material properties of grade ISO 3506 group A2 (304 / 1.4301), commonly supplied A2-70: good general corrosion resistance, largely non-magnetic, service range approx. -200 °C to +400 °C, subject to the property class and the joint. This page summarizes the grade data, its corrosion behavior in service, the comparable grades, and the sizes supplied.
Why Choose A2 Stainless Steel for Slotted Hex Nuts, UNC
The most common stainless group for indoor and general outdoor fasteners. For slotted hex nuts, unc, this matters when good general corrosion resistance is the primary requirement.
Mechanical & Physical Properties
| Grade designation | ISO 3506 group A2 (304 / 1.4301), commonly supplied A2-70 |
|---|---|
| Magnetic response | Largely non-magnetic |
| Service temperature | approx. -200 °C to +400 °C, subject to the property class and the joint |
| Corrosion characteristic | Good general corrosion resistance |
Galvanic & Galling Considerations
Two important notes for stainless slotted hex nuts, unc: (1) stainless can gall on stainless threads under load — use a thread lubricant or anti-galling compound, especially for M6 and below; (2) when joined to aluminum or galvanized steel, stainless can drive galvanic corrosion of the less-noble metal in wet service — isolate with a coating or sleeve where appropriate.
Comparable Grades
For Slotted Hex Nuts, UNC, the alternative stainless grade is A4 (316). A2 (304) covers general indoor and outdoor service. A4 (316) adds molybdenum, which is what buys the chloride resistance for marine and de-icing-salt exposure. Where strength matters more than corrosion, plated alloy steel in class 8.8 or 10.9 is the swap to make.
Using Stainless Fasteners in Aluminum
The galvanic couple here runs the wrong way: aluminum is the less noble metal, so it corrodes and the fastener does not. What governs the rate is the ratio of areas — a large anode and a small cathode is a tolerable combination, the reverse concentrates the attack into thin material around the hole. An isolating washer plus sealant breaks the circuit; where that is impractical, match the fastener to the substrate.
Sizes of Slotted Hex Nuts, UNC Available in A2 Stainless Steel
| Size | Threads per inch | Width across flats s (in) | Nut height m (in) | T (in) | S (in) | Reference standard |
|---|---|---|---|---|---|---|
| 1/4" | 20 | 0.438 | 0.219 | 0.13 | 0.085 | ASME B18.2.2 |
| 5/16" | 18 | 0.5 | 0.266 | 0.17 | 0.105 | ASME B18.2.2 |
| 3/8" | 16 | 0.562 | 0.328 | 0.2 | 0.135 | ASME B18.2.2 |
| 7/16" | 14 | 0.688 | 0.375 | 0.22 | 0.135 | ASME B18.2.2 |
| 1/2" | 13 | 0.75 | 0.438 | 0.28 | 0.165 | ASME B18.2.2 |
| 9/16" | 12 | 0.875 | 0.484 | 0.3 | 0.165 | ASME B18.2.2 |
| 5/8" | 11 | 0.938 | 0.547 | 0.33 | 0.21 | ASME B18.2.2 |
| 3/4" | 10 | 1.125 | 0.641 | 0.39 | 0.21 | ASME B18.2.2 |
| 7/8" | 9 | 1.312 | 0.75 | 0.505 | 0.21 | ASME B18.2.2 |
| 1" | 8 | 1.5 | 0.859 | 0.575 | 0.27 | ASME B18.2.2 |
| 1 1/8" | 7 | 1.688 | 0.969 | 0.625 | 0.285 | ASME B18.2.2 |
| 1 1/4" | 7 | 1.875 | 1.062 | 0.685 | 0.355 | ASME B18.2.2 |
| 1 3/8" | 6 | 2.062 | 1.172 | 0.8 | 0.355 | ASME B18.2.2 |
| 1 1/2" | 6 | 2.25 | 1.281 | 0.84 | 0.415 | ASME B18.2.2 |
Dimensions are independent of the material: every size above is available in A2 Stainless Steel.
Custom manufacturing · Made to drawing
Need this nut in a grade that is not listed?
A2 Stainless Steel is one of the grades the catalog describes. Locking method is specifiable independently of the rest: nylon insert, all-metal deformed thread, serrated flange, or none. Made by cold heading or tapping.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
