A4 Stainless Steel Swing Bolt — GB/T 77 / ISO 4026 (Series 020) pairs the standard GB/T 77 / ISO 4026 with a A4 Stainless Steel base material. The sections below cover why engineers select this grade for swing bolt — gb/t 77 / iso 4026 (series 020), its corrosion and temperature behavior, and the sizes available.
Why Choose A4 Stainless Steel for Swing Bolt — GB/T 77 / ISO 4026 (Series 020)
Specified for marine, coastal and chemical applications. For swing bolt — gb/t 77 / iso 4026 (series 020), 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 |
Galvanic & Galling Considerations
Two important notes for stainless swing bolt — gb/t 77 / iso 4026 (series 020): (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 Swing Bolt — GB/T 77 / ISO 4026 (Series 020), the alternative stainless grade is A2 (304). A2 (304) suits general indoor and outdoor service; A4 (316) adds molybdenum for marine and chloride environments. Where higher strength matters more than corrosion, switch to plated alloy-steel class 8.8 or 10.9.
Sizes of Swing Bolt — GB/T 77 / ISO 4026 (Series 020) Available in A4 Stainless Steel
| Thread size | Pitch (mm) | Ring outer dia D (mm) | Ring wire dia (mm) | Total length L (mm) | SWL (kg, axial) | Reference standard |
|---|---|---|---|---|---|---|
| M8 | 1.25 | 20 | 8 | 36 | 140 | DIN 580 / GB/T 825 |
| M10 | 1.5 | 25 | 10 | 45 | 230 | DIN 580 / GB/T 825 |
| M12 | 1.75 | 30 | 12 | 54 | 340 | DIN 580 / GB/T 825 |
| M16 | 2.0 | 35 | 14 | 63 | 700 | DIN 580 / GB/T 825 |
| M20 | 2.5 | 40 | 16 | 72 | 1200 | DIN 580 / GB/T 825 |
| M24 | 3.0 | 50 | 20 | 90 | 1800 | DIN 580 / GB/T 825 |
| M30 | 3.5 | 60 | 25 | 108 | 3200 | DIN 580 / GB/T 825 |
| M36 | 4.0 | 72 | 30 | 126 | 5000 | DIN 580 / GB/T 825 |