A4 Stainless Steel (ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80) is specified for marine, coastal and chemical applications. When panel clips and u-clips are specified in this grade, the dimensions remain per Trade series (edge-retaining panel clips); the material determines corrosion behavior (superior, including marine and chloride environments) and the service temperature range (approx. -200 °C to +400 °C, subject to the property class and the joint). Both are covered below with the size table.
Why Choose A4 Stainless Steel for Panel Clips and U-Clips
Specified for marine, coastal and chemical applications. For panel clips and u-clips, 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 panel clips and u-clips 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 Panel Clips and U-Clips, the alternative stainless grade is A2 (304). A2 (304) covers general indoor and outdoor service. A4 (316) adds molybdenum, which is what buys the chloride resistance for marine and de-icing-salt exposure. Where strength matters more than corrosion, plated alloy steel in class 8.8 or 10.9 is the swap to make.
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 Panel Clips and U-Clips Available in A4 Stainless Steel
| Panel thickness / series | Length (in or mm) | Width (in or mm) | Height (mm) | Metal thickness (mm) | Material |
|---|---|---|---|---|---|
| 0.05~0.10 in | 11/32 in | 1/2 in | black-phosphate steel / silver steel | ||
| 0.17~0.205 in | 7/16 in | 1/2 in | black-phosphate steel / silver steel | ||
| 0.245~0.255 in | 3/8 in | 1/2 in | black-phosphate steel / silver steel | ||
| 1.8 mm | 11.5 | 15.8 | 9.3 | 0.5 | silver steel |
| 1.8~2.5 mm | 14.3 | 12.7 | 11.7 | 0.5 | silver steel |
