Material specification page for nylon insert hex lock nut in A2 Stainless Steel. Covers the grade designation (ISO 3506 group A2 (304 / 1.4301), commonly supplied A2-70), corrosion and magnetic behavior, comparable grades and their trade-offs, and the sizes available to GB/T 889 / ISO 7040.
Why Choose A2 Stainless Steel for Nylon Insert Hex Lock Nut — GB/T 889 / ISO 7040 (Series 078)
The most common stainless group for indoor and general outdoor fasteners. For nylon insert hex lock nut — gb/t 889 / iso 7040 (series 078), 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 |
Corrosion Behavior in Service
A2 (304) gives excellent atmospheric and most-water corrosion resistance and is the most common stainless for Nylon Insert Hex Lock Nut — GB/T 889 / ISO 7040 (Series 078) in indoor and general outdoor service. In chloride-bearing environments (marine air, road salt, swimming pools) consider stepping up to A4 (316).
Comparable Grades
For Nylon Insert Hex Lock Nut — GB/T 889 / ISO 7040 (Series 078), the alternative stainless grade is A4 (316). Choose A2 (304) for general use and A4 (316) wherever chlorides are present; the molybdenum in A4 is the whole difference. Remember that stainless is the corrosion answer, not the strength answer — for load, look at class 8.8 or 10.9 instead.
Using Stainless Fasteners in Aluminum
Stainless steel is more noble than aluminum, so with an electrolyte present — rain, condensation, salt spray — the aluminum becomes the anode and corrodes at the joint. Area ratio decides how bad it gets: a small stainless fastener in a large aluminum section is normally acceptable, a large stainless fastener in thin aluminum is not. Where the joint gets wet, isolate the metals with a coated or nylon washer and a sealant, or specify an aluminum or coated fastener instead.
Sizes of Nylon Insert Hex Lock Nut — GB/T 889 / ISO 7040 (Series 078) Available in A2 Stainless Steel
| Size | Pitch (mm) | Width across flats s (mm) | Width across corners e (mm) | Total height m (mm) | Reference standard |
|---|---|---|---|---|---|
| M3 | 0.5 | 5.5 | 6.01 | 4.0 | ISO 7040 / DIN 985 |
| M4 | 0.7 | 7.0 | 7.66 | 5.0 | ISO 7040 / DIN 985 |
| M5 | 0.8 | 8.0 | 8.79 | 5.0 | ISO 7040 / DIN 985 |
| M6 | 1.0 | 10.0 | 11.05 | 6.0 | ISO 7040 / DIN 985 |
| M8 | 1.25 | 13.0 | 14.38 | 8.0 | ISO 7040 / DIN 985 |
| M10 | 1.5 | 16.0 | 17.77 | 10.0 | ISO 7040 / DIN 985 |
| M12 | 1.75 | 18.0 | 20.03 | 12.0 | ISO 7040 / DIN 985 |
| M14 | 2.0 | 21.0 | 23.36 | 14.0 | ISO 7040 / DIN 985 |
| M16 | 2.0 | 24.0 | 26.75 | 16.0 | ISO 7040 / DIN 985 |
| M18 | 2.5 | 27.0 | 30.14 | 18.0 | ISO 7040 / DIN 985 |
| M20 | 2.5 | 30.0 | 33.53 | 20.0 | ISO 7040 / DIN 985 |
| M24 | 3.0 | 36.0 | 39.98 | 22.0 | ISO 7040 / DIN 985 |
| M30 | 3.5 | 46.0 | 50.85 | 25.0 | ISO 7040 / DIN 985 |
| M36 | 4.0 | 55.0 | 60.79 | 29.0 | ISO 7040 / DIN 985 |
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. Height and across-flats are the two most often changed — a thinner nut for clearance, a larger hex for a tool that is already on the line. Made by cold heading or tapping.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
