When Hex Socket Flat Point Set Screw — GB/T 77 / ISO 4026 (Series 021) are required in A4 Stainless Steel, the alternative grades and the trade-offs between them matter as much as the dimensions. This page covers both, plus mechanical and corrosion data.
Why Choose A4 Stainless Steel for Hex Socket Flat Point Set Screw — GB/T 77 / ISO 4026 (Series 021)
Specified for marine, coastal and chemical applications. For hex socket flat point set screw — gb/t 77 / iso 4026 (series 021), 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 Hex Socket Flat Point Set Screw — GB/T 77 / ISO 4026 (Series 021) in marine, coastal, swimming-pool or food-processing environments, A4 is the default selection.
Galvanic & Galling Considerations
Two important notes for stainless hex socket flat point set screw — gb/t 77 / iso 4026 (series 021): (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 Hex Socket Flat Point Set Screw — GB/T 77 / ISO 4026 (Series 021) Available in A4 Stainless Steel
| Size | Pitch (mm) | Length L (mm) | Hex socket s (mm) | Engagement depth t min (mm) | Point diameter dp (mm) | Reference standard |
|---|---|---|---|---|---|---|
| M3 | 0.5 | 6 | 1.5 | 1.4 | 2.0 | ISO 4026-4029 / GB/T 77-79 |
| M4 | 0.7 | 6 | 2.0 | 2.0 | 2.5 | ISO 4026-4029 / GB/T 77-79 |
| M5 | 0.8 | 7 | 2.5 | 2.5 | 3.5 | ISO 4026-4029 / GB/T 77-79 |
| M6 | 1.0 | 9 | 3.0 | 3.0 | 4.0 | ISO 4026-4029 / GB/T 77-79 |
| M8 | 1.25 | 12 | 4.0 | 4.0 | 5.5 | ISO 4026-4029 / GB/T 77-79 |
| M10 | 1.5 | 15 | 5.0 | 5.0 | 7.0 | ISO 4026-4029 / GB/T 77-79 |
| M12 | 1.75 | 18 | 6.0 | 6.0 | 8.5 | ISO 4026-4029 / GB/T 77-79 |
| M16 | 2.0 | 24 | 8.0 | 8.0 | 12.0 | ISO 4026-4029 / GB/T 77-79 |
| M20 | 2.5 | 30 | 10.0 | 10.0 | 15.0 | ISO 4026-4029 / GB/T 77-79 |
| M24 | 3.0 | 36 | 12.0 | 12.0 | 18.0 | ISO 4026-4029 / GB/T 77-79 |
