Quick answer: when people search for a "1/4 rubber washer" they almost always mean a washer with a 1/4" inside diameter (ID), the hole that fits a 1/4" bolt, screw or stud. We list 162 sizes with a 1/4" hole, with outside diameters from 7/16" to 4" and thicknesses from 1/32" to 1/2", each in seven rubber materials. Choose the OD by how much surface the washer must cover, the thickness by the job (sealing, cushioning or spacing), and the material by the environment. All of them are in the 1/4" ID rubber washers collection.
1/4" is one of the most common fastener sizes in North America. It covers 1/4"-20 and 1/4"-28 machine bolts, 1/4" lag screws, many panel and enclosure screws, and the studs on a lot of household and automotive hardware. A rubber washer on that fastener seals the hole against water, cushions a fragile part, stops rattles, or isolates two metals from each other.
Is it the hole or the outside that's 1/4"?
A washer has three dimensions: outside diameter (OD), inside diameter (ID) and thickness. "1/4" in a washer name nearly always refers to the ID. A washer that is 1/4" across the outside is tiny. We list only three, each with a 1/8" hole, such as the 1/4" OD x 1/8" ID x 1/16" washer. If you're not sure which you need, measure the old washer as shown in how to measure a rubber washer.
Matching the hole to the fastener
- 1/4" bolts and studs (1/4"-20, 1/4"-28): a 1/4" ID gives a snug fit that stays centred and seals around the shank. Rubber stretches a little, so the washer slides on easily.
- #14 screws and some sheet-metal screws are close to 1/4" across the thread. A 1/4" ID is usually right; measure the screw if in doubt.
- M6 metric bolts are 6 mm, slightly smaller than 1/4" (6.35 mm). A 1/4" ID fits over an M6 bolt with a little play. For a closer seal, see our M6 rubber washers guide.
- Want it to slide on freely? Step up to a 5/16" ID. That is useful for spacers and cushions where sealing doesn't matter.
Every 1/4" ID size we list
Each outside diameter below is listed in the thicknesses shown, and every size is offered in neoprene, EPDM, nitrile, silicone, natural rubber, Viton and fiber. Stock varies by size and material.
| OD with a 1/4" hole | Thicknesses listed |
|---|---|
| 7/16" | 1/16", 3/32", 1/8", 3/16", 1/4", 3/8", 1/2" |
| 1/2" | 1/16", 3/32", 1/8", 3/16", 1/4", 3/8", 1/2" |
| 9/16" | 1/16", 3/32", 1/8", 3/16", 1/4", 3/8", 1/2" |
| 5/8" | 1/16", 3/32", 1/8", 3/16", 1/4", 3/8", 1/2" |
| 11/16" | 1/16", 3/32", 1/8", 3/16", 1/4", 3/8", 1/2" |
| 3/4" | 1/16", 3/32", 1/8", 3/16", 1/4", 3/8", 1/2" |
| 13/16" | 1/16", 3/32", 1/8", 3/16", 1/4", 3/8", 1/2" |
| 7/8" | 1/32", 1/16", 3/32", 1/8", 3/16", 1/4", 3/8", 1/2" |
| 15/16" | 1/16", 3/32", 1/8", 3/16", 1/4", 3/8", 1/2" |
| 1" | 1/16", 3/32", 1/8", 3/16", 1/4", 3/8", 1/2" |
| 1-1/8" | 1/16", 3/32", 1/8", 3/16", 1/4", 3/8", 1/2" |
| 1-1/4" | 1/16", 3/32", 1/8", 3/16", 1/4", 3/8", 1/2" |
| 1-3/8" | 1/16", 3/32", 1/8", 3/16", 1/4", 3/8", 1/2" |
| 1-1/2" | 1/16", 3/32", 1/8", 3/16", 1/4", 3/8", 1/2" |
| 1-5/8" | 1/16", 3/32", 1/8", 3/16", 1/4", 3/8", 1/2" |
| 1-3/4" | 1/16", 3/32", 1/8", 3/16", 1/4", 3/8", 1/2" |
| 2" | 1/16", 3/32", 1/8", 3/16", 1/4", 3/8", 1/2" |
| 2-1/4" | 1/16", 3/32", 1/8", 3/16", 1/4", 3/8", 1/2" |
| 2-1/2" | 1/16", 3/32", 1/8", 3/16", 1/4", 3/8", 1/2" |
| 2-3/4" | 1/16", 3/32", 1/8", 3/16", 1/4", 3/8", 1/2" |
| 3" | 1/16", 3/32", 1/8", 3/16", 1/4", 3/8", 1/2" |
| 3-1/2" | 1/16", 3/32", 1/8", 3/16", 1/4", 3/8", 1/2" |
| 4" | 1/16", 3/32", 1/8", 3/16", 1/4", 3/8", 1/2" |
Need a different hole or OD? The full rubber washer size chart lists every OD, ID and thickness combination in inch and mm.
Choosing the outside diameter
The OD sets how much surface the washer covers around the hole. For a bolt through metal, an OD of roughly two to three times the bolt size (about 1/2" to 3/4" for a 1/4" bolt) is common and keeps the washer neat. Go larger when:
- the bolt passes through soft or thin material such as plastic, fiberglass, canvas or thin sheet metal, and you want to spread the clamping force;
- you need to cover an oversized, worn or damaged hole;
- the washer is acting as a bumper or cushion as well as a seal.
Make sure the OD clears nearby edges, ribs or other fasteners. Our size finder filters the catalogue by OD, ID and thickness at once.
Choosing the thickness
- 1/32" to 1/16": thin seals and shims on flat, smooth faces, or under a screw head where height matters.
- 3/32" to 1/8": the all-round choice for sealing and anti-rattle use.
- 3/16" to 1/2": cushioning, vibration isolation, taking up gaps, and spacing. See thick and large rubber washers.
A thicker washer isn't automatically a better seal. When tightened, thick rubber bulges out sideways. For sealing two flat faces, 1/16" to 1/8" usually works best.
Choosing the material
| Material | Usual choice for |
|---|---|
| Neoprene | All-purpose sealing and cushioning, indoors and out |
| EPDM | Water, steam, sunlight and ozone; not petroleum oils |
| Nitrile | Oil, fuel and grease |
| Silicone | High and low temperatures, food-contact equipment |
| Viton | Aggressive chemicals, fuels and high heat |
| Natural rubber | Shock and vibration absorption |
| Fiber | Firm, dry gasketing on fittings |
The rubber washer material guide compares all seven by temperature range and chemical resistance.
1/4" washers ready to ship (October 2026)
These 1/4" ID sizes, plus the small 1/4" OD sizes, had at least one material in stock when this guide was updated. Other sizes show as sold out on their product page until they are restocked.
| OD | ID | Thick | In stock in | |
|---|---|---|---|---|
| 7/8" | 1/4" | 1/32" | Neoprene | View size |
| 2" | 1/4" | 1/8" | Neoprene | View size |
| 1-1/2" | 1/4" | 1/16" | Neoprene | View size |
| 3/4" | 1/4" | 3/16" | Silicone | View size |
| 3/4" | 1/4" | 1/8" | Neoprene | View size |
| 3/4" | 1/4" | 3/32" | Neoprene | View size |
| 3/4" | 1/4" | 1/16" | Silicone | View size |
| 5/8" | 1/4" | 3/32" | EPDM | View size |
| 5/8" | 1/4" | 1/16" | Neoprene | View size |
| 1/2" | 1/4" | 3/32" | EPDM | View size |
| 1/4" | 1/8" | 1/32" | Neoprene | View size |
| 1/4" | 1/8" | 1/16" | Neoprene | View size |
| 1/4" | 1/8" | 3/32" | EPDM | View size |
FAQ
What size rubber washer fits a 1/4" bolt?
A washer with a 1/4" inside diameter. Then choose an OD (commonly 1/2" to 3/4") and a thickness that suit the job.
Will a 1/4" rubber washer fit an M6 bolt?
Yes, with slight play, because M6 is about 0.236" and 1/4" is 0.250". For a snug metric fit, see M6 rubber washers.
What does "1/4 rubber washer" mean on a hardware list?
Usually a washer for a 1/4" fastener, which means a 1/4" ID. The OD and thickness should be listed separately. If they aren't, measure the original.
Which material should I use for a 1/4" washer outdoors?
EPDM or neoprene for weather and sunlight. Use nitrile instead if the washer will touch oil or fuel.