A2 Stainless Steel Round Shims, Inch Series are supplied to our own published dimensions — this is a trade-series article rather than one covered by a dimensional standard, so confirm the figures against the part you are replacing. The grade provides good general corrosion resistance and is largely non-magnetic; the practical service range is approx. -200 °C to +400 °C, subject to the property class and the joint.
Why Choose A2 Stainless Steel for Round Shims, Inch Series
The most common stainless group for indoor and general outdoor fasteners. For round shims, inch series, this matters when good general corrosion resistance is the primary requirement.
Mechanical & Physical Properties
| Grade designation | ISO 3506 group A2 (304 / 1.4301), commonly supplied A2-70 |
|---|---|
| Magnetic response | Largely non-magnetic |
| Service temperature | approx. -200 °C to +400 °C, subject to the property class and the joint |
| Corrosion characteristic | Good general corrosion resistance |
Galvanic & Galling Considerations
For stainless round shims, inch series 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 Round Shims, Inch Series, the alternative stainless grade is A4 (316). 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 Round Shims, Inch Series Available in A2 Stainless Steel
| Bore (in) | Outer diameter (in) | Thickness (in) | Thickness (mm) | Tolerance | Material | Typical use | Stack step |
|---|---|---|---|---|---|---|---|
| 1/4 | 1/2 | 0.001 | 0.025 | ±0.0002 | Stainless 302 | Bearing preload | 0.001" |
| 1/4 | 1/2 | 0.005 | 0.127 | ±0.0005 | Stainless 302 | Bearing preload | 0.005" |
| 3/8 | 5/8 | 0.002 | 0.051 | ±0.0003 | Stainless 302 | Gear backlash | 0.002" |
| 1/2 | 7/8 | 0.005 | 0.127 | ±0.0005 | Stainless 302 | Gear backlash | 0.005" |
| 1/2 | 7/8 | 0.010 | 0.254 | ±0.001 | Stainless 302 | Pulley alignment | 0.010" |
| 3/4 | 1-1/4 | 0.010 | 0.254 | ±0.001 | Stainless 302 | Pulley alignment | 0.010" |
| 1 | 1-1/2 | 0.020 | 0.508 | ±0.001 | Stainless 302 | Shaft end float | 0.020" |
Dimensions are independent of the material: every size above is available in A2 Stainless Steel.
Custom manufacturing · Made to drawing
Need this standoff & spacer in a grade that is not listed?
A2 Stainless Steel is one of the grades the catalog describes. A non-standard standoff & spacer is quoted from the drawing; where one already exists in the catalog, the special is usually a variation on its tooling. Made by tapping or turning.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
