A4 Stainless Steel Shoulder Bolts are stocked to ISO 7379. The grade provides superior, including marine and chloride environments and is largely non-magnetic; the practical service range is approx. -200 °C to +400 °C. Property data, grade comparison and the full size table follow.
Why Choose A4 Stainless Steel for Shoulder Bolts
Specified for marine, coastal and chemical applications. For shoulder bolts, 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 Shoulder Bolts in marine, coastal, swimming-pool or food-processing environments, A4 is the default selection.
Galvanic & Galling Considerations
Two important notes for stainless shoulder bolts: (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 Shoulder Bolts Available in A4 Stainless Steel
| Shoulder diameter (mm) | Thread size | Pitch (mm) | Shoulder length range (mm) | Head diameter dk (mm) | Head height k (mm) | Reference standard |
|---|---|---|---|---|---|---|
| 4.0 | M3 | 0.5 | 8~50 | 8.0 | 4.3 | ISO 7379 / DIN 9841 |
| 5.0 | M4 | 0.7 | 8~63 | 9.5 | 5.3 | ISO 7379 / DIN 9841 |
| 6.0 | M5 | 0.8 | 10~63 | 11.0 | 6.5 | ISO 7379 / DIN 9841 |
| 8.0 | M6 | 1.0 | 10~80 | 13.0 | 8.0 | ISO 7379 / DIN 9841 |
| 10.0 | M8 | 1.25 | 12~100 | 16.0 | 10.0 | ISO 7379 / DIN 9841 |
| 12.0 | M10 | 1.5 | 16~100 | 18.0 | 12.0 | ISO 7379 / DIN 9841 |
| 16.0 | M12 | 1.75 | 20~125 | 24.0 | 16.0 | ISO 7379 / DIN 9841 |
| 20.0 | M16 | 2.0 | 25~160 | 30.0 | 20.0 | ISO 7379 / DIN 9841 |
| 25.0 | M20 | 2.5 | 32~200 | 36.0 | 25.0 | ISO 7379 / DIN 9841 |
| 30.0 | M24 | 3.0 | 40~200 | 45.0 | 30.0 | ISO 7379 / DIN 9841 |