A4 Stainless Steel Two-Piece Clamp Shaft Collars are supplied to Trade series (two-piece clamp-type shaft collars). 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, subject to the property class and the joint. Property data, grade comparison and the full size table follow.
Why Choose A4 Stainless Steel for Two-Piece Clamp Shaft Collars
Specified for marine, coastal and chemical applications. For two-piece clamp shaft collars, this matters when superior, including marine and chloride environments is the primary requirement.
Mechanical & Physical Properties
| Grade designation | ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80 |
|---|---|
| Magnetic response | Largely non-magnetic |
| Service temperature | approx. -200 °C to +400 °C, subject to the property class and the joint |
| 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 Two-Piece Clamp Shaft Collars in marine, coastal, swimming-pool or food-processing environments, A4 is the default selection.
Galvanic & Galling Considerations
For stainless two-piece clamp shaft collars the compatibility question is galvanic rather than galling: joined to aluminum or galvanized steel in wet service, stainless drives corrosion of the less-noble metal. Isolate with a coating, sleeve or non-conductive washer where the joint sees moisture. Note also that stainless is softer than hardened carbon steel, so where the part carries a wear or shear duty, check the load against the grade before substituting.
Using Stainless Fasteners in Aluminum
Expect the aluminum to corrode, not the fastener — stainless sits higher in the galvanic series, so the aluminum is the one that gives up material. A small fastener in a thick section spreads the loss over a large area and is usually fine; a large fastener in thin sheet concentrates it and is not. Keep water out of the joint, or isolate the two metals with a nylon or coated washer and a sealant.
Sizes of Two-Piece Clamp Shaft Collars Available in A4 Stainless Steel
| Bore (mm) | Outside diameter (mm) | Width (mm) | Clamp screws |
|---|---|---|---|
| 8 | 24 | 12 | two M3 socket head cap screws |
| 10 | 28 | 13 | two M4 socket head cap screws |
| 12 | 30 | 13 | two M4 socket head cap screws |
| 15 | 36 | 15 | two M5 socket head cap screws |
| 16 | 38 | 15 | two M5 socket head cap screws |
| 20 | 45 | 17 | two M5 socket head cap screws |
| 25 | 50 | 17 | two M6 socket head cap screws |
| 30 | 60 | 19 | two M6 socket head cap screws |
| 35 | 65 | 19 | two M8 socket head cap screws |
| 40 | 70 | 21 | two M8 socket head cap screws |
