What are Rivet Washers?
Rivet washers, also called backup washers, are flat rings used with blind rivets to increase the bearing area on the blind side. They help prevent pull-through in thin or soft materials and improve support when a hole is slightly oversized or irregular.
When should I use a rivet backing washer?
- Thin sheet where a standard head might pull through
- Soft substrates like plastics, fiberglass, or soft aluminum
- Repairs with worn or slightly oblong holes
- Any joint that needs a larger load-spreading surface behind the panel
What size washer for 1/8 in and 3/16 in rivets?
Match the washer’s inside diameter to the rivet size so it slides over the body with minimal play, then choose an outside diameter that gives adequate bearing on your material. Typical pairings are below.
| Rivet size | Typical washer ID (in) | Typical washer OD (in) | Common thickness (in) |
|---|---|---|---|
| 1/8 in | ≈ 0.132 to 0.136 | ≈ 0.375 | ≈ 0.062 |
| 5/32 in | ≈ 0.163 to 0.167 | ≈ 0.437 | ≈ 0.062 |
| 3/16 in | ≈ 0.195 to 0.199 | ≈ 0.500 | ≈ 0.062 |
| 1/4 in | ≈ 0.260 to 0.264 | ≈ 0.562 | ≈ 0.062 |
Notes: ID should closely fit the rivet body for proper support. OD can be increased for very soft or thin materials.
Should the washer material match the rivet?
Matching materials reduces the chance of galvanic corrosion. Stainless rivet with stainless washer, aluminum rivet with aluminum washer, and so on. If mixing metals in wet or marine settings, use barriers or sealants to isolate dissimilar metals.
Installation & best practices
- Drill to the correct size for the rivet and deburr both sides.
- Place the washer on the blind side with the rivet body through the washer and workpiece.
- Seat the visible head flat, keep the tool square, and pull until the mandrel snaps.
- For very soft sheet, consider a larger OD washer or step up rivet diameter.
Troubleshooting & quick fixes
- Washer digs into material, OD too small or material too soft, use a larger OD washer or large flange rivet on the visible side.
- Rivet spins during pull, hole oversized, move up a diameter or ensure the washer ID closely fits the rivet body.
- Corrosion at joint, dissimilar metals in a wet environment, match materials or isolate with sealant or nonconductive washers.
Common materials & uses
- Aluminum washers: low weight, good with aluminum panels, plastics, fiberglass
- Steel or zinc-plated steel: economical bearing surface for general sheet metal
- 304 stainless: corrosion resistance for outdoor or damp locations
Why buy Rivet Washers from AlbanyCountyFasteners.com
- Aluminum, zinc-plated steel, and stainless options
- Sizes matched to common blind rivet diameters
- Bulk packs for shop and jobsite use
- USA-based support for sizing and material pairing
FAQs
Short answers to help you size and use rivet backup washers with confidence.
Do I need a washer with every blind rivet?
No. Use them when you need extra bearing area, when material is thin or soft, or when a hole is slightly oversized.
Which side gets the washer?
On the blind side, under the rivet’s formed end.
Can I stack two washers?
It is possible for very soft materials, but a larger OD single washer is usually better.
What if I see corrosion where stainless rivets meet galvanized steel?
That can be galvanic action in wet environments. Match materials or isolate the metals with sealant or barriers.
Do washers change the drill size?
No. Drill for the rivet body. The washer ID is made to fit the same rivet size.