An M10 bolt is 10.00 mm (0.394") in diameter. The nearest stocked ID is 3/8" (9.53 mm), which stretches on for a snug sealing fit; 7/16" (11.11 mm) gives a clearance fit. All sizes ship in seven rubber materials.
Best in-stock matches for M10
| Washer size | Fit |
|---|---|
| 3/4" OD × 3/8" ID × 1/16" | Snug, compact |
| 1" OD × 3/8" ID × 1/16" | Snug, wider face |
| 1-1/4" OD × 3/8" ID × 1/8" | Fender-style, more compression |
| 1-1/2" OD × 3/8" ID × 1/8" | Maximum coverage |
Browse all 3/8" ID and 7/16" ID rubber washers.
Sizing note
The 0.47 mm interference on a 3/8" ID makes the washer grip an M10 shank firmly — ideal for sealing under bolt heads. Use 7/16" ID when the washer must slide freely, such as on carriage bolts or through-fixings.
More metric bolts: M4 · M5 · M6 · M8 · M12 · M16 · M20 — or see the metric conversion guide, Size Finder and size chart.
FAQ
What size rubber washer fits an M10 bolt?
A 3/8" (9.53 mm) ID rubber washer stretches onto a 10 mm M10 bolt for a snug fit; a 7/16" (11.11 mm) ID slides on freely.
Which thickness should I choose for M10?
1/16" for flat machined faces, 1/8" for general sealing and vibration, 3/16"–1/4" for irregular surfaces or spacing duty.