Material page for quick-release pin retaining caps in A4 Stainless Steel (ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80). The sizes below are the ones we supply; there is no published dimensional standard for this article, so the table rather than a standard number is what to quote. Corrosion behaviour is superior, including marine and chloride environments and the service range is approx. -200 °C to +400 °C, subject to the property class and the joint.
Why Choose A4 Stainless Steel for Quick-Release Pin Retaining Caps
Specified for marine, coastal and chemical applications. For quick-release pin retaining caps, 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 Quick-Release Pin Retaining Caps in marine, coastal, swimming-pool or food-processing environments, A4 is the default selection.
Comparable Grades
For Quick-Release Pin Retaining Caps, the alternative stainless grade is A2 (304). The practical dividing line is chlorides: A2 (304) is fine until salt is involved, and A4 (316) exists for the cases where it is — coastal, marine and road-salt service. Neither reaches the strength of a plated class 8.8 or 10.9 fastener.
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 Quick-Release Pin Retaining Caps Available in A4 Stainless Steel
| Pin diameter | Cap OD | Overall length | Usable reduction | Material | Option |
|---|---|---|---|---|---|
| 3/16 in | 3/8 in | 9/16 in | 1/8 in | 18-8 stainless steel | optional lanyard screw |
| 1/4 in | 3/8 in | 9/16 in | 1/8 in | 18-8 stainless steel | optional lanyard screw |
| 5/16 in | 1/2 in | 5/8 in | 1/8 in | 18-8 stainless steel | optional lanyard screw |
| 3/8 in | 9/16 in | 3/4 in | 3/16 in | 18-8 stainless steel | optional lanyard screw |
| 1/2 in | 3/4 in | 1 in | 1/4 in | 18-8 stainless steel | optional lanyard screw |
| 5/8 in | 1 in | 1-1/4 in | 1/4 in | 18-8 stainless steel | optional lanyard screw |
| 6 / 8 / 10 / 12 / 16 mm | 9.5 / 12.7 / 14.3 / 19.1 / 25.4 | 14.7 / 15.9 / 18.5 / 25.4 / 31.8 | 3 / 3 / 5 / 6 / 6 mm | 18-8 stainless steel | optional lanyard screw |
Dimensions are independent of the material: every size above is available in A4 Stainless Steel.
Custom manufacturing · Made to drawing
Need this pin in a grade that is not listed?
A4 Stainless Steel is one of the grades the catalog describes. Diameter, length, tolerance class, hardness and end form are specifiable. Ground diameters are held after heat treatment rather than before. Made by cold heading or turning.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
