One-Piece Clamp Shaft Collars manufactured in A4 Stainless Steel (ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80) are dimensioned to Trade series (one-piece clamp-type shaft collars). The sections below give the mechanical and physical properties of the grade, its behavior in corrosive and elevated-temperature service, and the full size table.
Why Choose A4 Stainless Steel for One-Piece Clamp Shaft Collars
Specified for marine, coastal and chemical applications. For one-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 One-Piece Clamp Shaft Collars in marine, coastal, swimming-pool or food-processing environments, A4 is the default selection.
Comparable Grades
For One-Piece Clamp Shaft Collars, the alternative stainless grade is A2 (304). Choose A2 (304) for general use and A4 (316) wherever chlorides are present; the molybdenum in A4 is the whole difference. Remember that stainless is the corrosion answer, not the strength answer — for load, look at class 8.8 or 10.9 instead.
Using Stainless Fasteners in Aluminum
The galvanic couple here runs the wrong way: aluminum is the less noble metal, so it corrodes and the fastener does not. What governs the rate is the ratio of areas — a large anode and a small cathode is a tolerable combination, the reverse concentrates the attack into thin material around the hole. An isolating washer plus sealant breaks the circuit; where that is impractical, match the fastener to the substrate.
Sizes of One-Piece Clamp Shaft Collars Available in A4 Stainless Steel
| Bore (mm) | Outside diameter (mm) | Width (mm) | Clamp screw |
|---|---|---|---|
| 6 | 18 | 9 | M3 socket head cap screw |
| 8 | 20 | 9 | M3 socket head cap screw |
| 10 | 24 | 11 | M4 socket head cap screw |
| 12 | 26 | 11 | M4 socket head cap screw |
| 15 | 32 | 14 | M5 socket head cap screw |
| 16 | 34 | 14 | M5 socket head cap screw |
| 20 | 40 | 15 | M5 socket head cap screw |
| 25 | 45 | 15 | M6 socket head cap screw |
| 30 | 54 | 18 | M6 socket head cap screw |
| 35 | 60 | 18 | M8 socket head cap screw |
| 40 | 66 | 20 | M8 socket head cap screw |
