Oil Resistant O-Ring Cord Stock
115 Products
What Is Oil-Resistant O-Ring Cord Stock?
Cord stock is uncut NBR (Buna-N) rubber cord sold in fixed lengths rather than pre-formed rings, so it can be cut and bonded into a custom O-ring in a size that isn't stocked as a finished part. LILY Bearing carries this cord in three cross-section shapes — round, X-profile, and square — rated from −25°F to +212°F, a narrower range than pre-formed oil-resistant O-rings.
Shop by Cross Section Shape
| Shape | Temperature Range | Hardness Options | Best Suited For | Note |
|---|---|---|---|---|
| Round | −25°F to +212°F | 50A, 70A, 90A | Custom-sized rings, widest hardness selection | Available in black or white depending on hardness |
| X (Quad-Ring) | −25°F to +212°F | 70A | Custom dynamic seals needing reduced friction | Same temperature rating as round |
| Square | −25°F to +212°F | 70A | Custom static seals, cost-sensitive builds | Same temperature rating as round |
Cord stock is sold in fixed cut lengths rather than by finished ring size. Customers bond the cut length into a ring sized for their specific gland, which is why cord stock is the go-to option when a needed O-ring size isn't available as a pre-formed part.
Where Is Oil-Resistant Cord Stock Used?
- Custom or oversized gasket and seal repairs
- Field service where a stock O-ring size isn't on hand
- Legacy or discontinued equipment with non-standard bores
- Prototype and low-volume seal fabrication
Frequently Asked Questions
Why is cord stock's temperature range narrower than pre-formed oil-resistant O-rings?
Cord stock is rated to 212°F versus 250°F for pre-formed round O-rings in the same NBR family. If your application runs above 212°F, a pre-formed O-ring in the standard size range is likely a better fit than a custom-bonded ring.
When should I use cord stock instead of a standard O-ring?
Use cord stock when you need a size that isn't available as a finished O-ring — oversized bores, discontinued equipment, or one-off repairs. For a standard size, a pre-formed O-ring is faster to install and doesn't require a bonded joint.
Does the bonded joint on a cord-stock ring weaken the seal?
A properly bonded joint holds up well in most static and light-duty sealing applications, though it's generally not recommended for high-pressure or highly dynamic service where a molded, seamless O-ring performs more reliably.
