A4 Stainless Steel Coiled Spring Pins, Heavy Duty combine the dimensional form of ISO 8748 with the material properties of grade ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80: superior, including marine and chloride environments, largely non-magnetic, service range approx. -200 °C to +400 °C, subject to the property class and the joint. This page summarizes the grade data, its corrosion behavior in service, the comparable grades, and the sizes supplied.
Why Choose A4 Stainless Steel for Coiled Spring Pins, Heavy Duty
Specified for marine, coastal and chemical applications. For coiled spring pins, heavy duty, 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 |
Galvanic & Galling Considerations
For stainless coiled spring pins, heavy duty 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.
Comparable Grades
For Coiled Spring Pins, Heavy Duty, 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
Stainless steel is more noble than aluminum, so with an electrolyte present — rain, condensation, salt spray — the aluminum becomes the anode and corrodes at the joint. Area ratio decides how bad it gets: a small stainless fastener in a large aluminum section is normally acceptable, a large stainless fastener in thin aluminum is not. Where the joint gets wet, isolate the metals with a coated or nylon washer and a sealant, or specify an aluminum or coated fastener instead.
Sizes of Coiled Spring Pins, Heavy Duty Available in A4 Stainless Steel
| Nominal diameter d (mm) | d_1 (mm) | d_2 (mm) | a (mm) | s (mm) | Length range l (mm) | Reference standard |
|---|---|---|---|---|---|---|
| 1.5 mm | 1.66 | 1.4 | 0.5 | 0.17 | 4~26 | ISO 8748 |
| 2 mm | 2.16 | 1.9 | 0.7 | 0.22 | 4~40 | ISO 8748 |
| 2.5 mm | 2.675 | 2.4 | 0.7 | 0.28 | 5~45 | ISO 8748 |
| 3 mm | 3.185 | 2.9 | 0.9 | 0.33 | 6~50 | ISO 8748 |
| 3.5 mm | 3.715 | 3.4 | 1 | 0.39 | 6~50 | ISO 8748 |
| 4 mm | 4.225 | 3.9 | 1.1 | 0.45 | 8~60 | ISO 8748 |
| 5 mm | 5.25 | 4.85 | 1.3 | 0.56 | 10~60 | ISO 8748 |
| 6 mm | 6.29 | 5.85 | 1.5 | 0.67 | 12~75 | ISO 8748 |
| 8 mm | 8.4 | 7.8 | 2 | 0.9 | 16~120 | ISO 8748 |
| 10 mm | 10.475 | 9.75 | 2.5 | 1.1 | 20~120 | ISO 8748 |
| 12 mm | 12.55 | 11.7 | 3 | 1.3 | 24~160 | ISO 8748 |
| 14 mm | 14.625 | 13.6 | 3.5 | 1.6 | 28~200 | ISO 8748 |
| 16 mm | 16.65 | 15.6 | 4 | 1.8 | 35~200 | ISO 8748 |
| 20 mm | 20.7 | 19.6 | 4.5 | 2.2 | 45~200 | ISO 8748 |
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.
