Specifying All-Metal Prevailing Torque Hex Lock Nut (Type 1) — GB/T 6184 / ISO 7042 (Series 047) in A4 Stainless Steel pairs the dimensional form of All-Metal Prevailing Torque Hex Lock Nut (Type 1) — GB/T 6184 / ISO 7042 (Series 047) (GB/T 6184 / ISO 7042) with the engineering properties of A4 Stainless Steel. This page explains when to choose the grade, how it behaves in service, and which grades to compare it against.
Why Choose A4 Stainless Steel for All-Metal Prevailing Torque Hex Lock Nut (Type 1) — GB/T 6184 / ISO 7042 (Series 047)
Specified for marine, coastal and chemical applications. For all-metal prevailing torque hex lock nut (type 1) — gb/t 6184 / iso 7042 (series 047), this matters when superior, including marine and chloride environments is the primary requirement.
Mechanical & Physical Properties
| Grade designation | A4-80 (316) |
|---|---|
| Magnetic response | Largely non-magnetic |
| Service temperature | approx. -200 °C to +400 °C |
| Corrosion characteristic | Superior, including marine and chloride environments |
Corrosion Behavior in Service
A4 (316) adds 2–3% molybdenum to the A2 (304) composition, which dramatically improves resistance to chloride-pitting corrosion. For All-Metal Prevailing Torque Hex Lock Nut (Type 1) — GB/T 6184 / ISO 7042 (Series 047) in marine, coastal, swimming-pool or food-processing environments, A4 is the default selection.
Galvanic & Galling Considerations
Two important notes for stainless all-metal prevailing torque hex lock nut (type 1) — gb/t 6184 / iso 7042 (series 047): (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.
Sizes of All-Metal Prevailing Torque Hex Lock Nut (Type 1) — GB/T 6184 / ISO 7042 (Series 047) Available in A4 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 |