Buna-N (Nitrile) Rubber Washers
Buna-N (Nitrile, NBR) rubber washers are the default specification when a washer must seal, cushion, or insulate under fuel, oil, hydraulic fluid, or grease contact. Cannon Gasket die-cuts custom Buna-N washers for fuel-system bolted joints, hydraulic flange isolators, pump body sealing, and automotive sealing washers. Available in commercial, high-grade, FDA, and cloth-inserted grades.
- Durometer
- 10A to 90A
- Highlight
- Excellent oil/fuel resistance
Request a quote for Buna-N / Nitrile rubber washers.
Properties of Buna-N / Nitrile rubber washers
Cannon Gasket cuts Buna-N / Nitrile rubber washers to your drawing specifications in durometers ranging from 10A to 90A Shore hardness. Material exhibits good resistance to petroleum oils, fuels, gasoline, greases, hydraulic fluids, water, and silicone greases.
Buna-N / Nitrile tolerances and customization
Standard dimensional tolerances on Buna-N / Nitrile rubber washers land around ±0.010" to ±0.015" on OD and ID, depending on material durometer and thickness. Tighter tolerances are available on selected grades. Cannon Gasket cuts Buna-N / Nitrile to custom profiles in-house and matches lead times to your production volume. PSA backing, pad printing, custom packaging, and kitting are all on the menu when you need them.
How Buna-N Performs in Washer Applications
- Excellent resistance to petroleum oils, fuels, hydraulic fluid, and greases. - Service temperature range -40°F to +250°F. - Durometer range 10 to 90 Shore A — softer for sealing, harder for load-bearing. - Compresses and recovers consistently across the bolt-load range typical of OEM assemblies.
Common Washer Applications
Fuel-tank and fuel-line sealing washers, hydraulic and pneumatic fitting washers, pump body bolt isolators, automotive bolt sealing washers, and plumbing equipment service.
When Another Material Is the Better Specification
For water, steam, or outdoor (UV / ozone) exposure, specify EPDM. For aggressive chemicals or temperature above 250°F, Viton. For abrasion resistance under wear loads, polyurethane.
Manufacturing Methods
Die-cut for tighter tolerance applications and ID to OD concentricity. Lathe-cut from Buna-N tube when thickness exceeds sheet stock. PSA backing common for service-kit installation.
Standard sizes, tolerances & manufacturing
Precision & tooling: Capable of holding tolerances as tight as ±.001" on critical dimensions when required, beyond the ±0.010" to ±0.015" standard. Short- and long-run capabilities. All parts available with pressure-sensitive adhesive (PSA) on one or two sides.
Clean room: Cannon Gasket offers clean-environment stamping for medical, FDA, electronic, and scientific applications where a controlled level of particulate is required, with capabilities to meet ISO Class 10,000.
Stocking agreements: Blanket orders, VMI (vendor-managed inventory), JIT (just-in-time), and Kanban replenishment programs.
Pad printing: Pad print your part number, identification marking, or company name in a range of ink colors. Marking per customer specifications or MIL-STD-130.
Packaging: Parts are bagged and tagged in specified quantities and labeled with P/N or any required information. Capability to meet specific packaging and labeling requirements.
Standard Screw Size Rubber Washers
| Screw Size | Outside Diameter | Inside Diameter | Thickness |
|---|---|---|---|
| #6 Standard | 0.250" | 0.120" | 0.015" – 0.250" |
| #6 Option | 0.375" | 0.120" | 0.015" – 0.250" |
| #8 Standard | 0.312" | 0.150" | 0.015" – 0.250" |
| #8 Option | 0.438" | 0.150" | 0.015" – 0.250" |
| #10 Standard | 0.375" | 0.170" | 0.015" – 0.250" |
| #10 Option | 0.500" | 0.170" | 0.015" – 0.250" |
| #12 Standard | 0.437" | 0.195" | 0.015" – 0.250" |
| #12 Option | 0.562" | 0.195" | 0.015" – 0.250" |
| #14 Standard | 0.500" | 0.230" | 0.015" – 0.250" |
| #14 Option | 0.625" | 0.230" | 0.015" – 0.250" |
| 5/16" Standard | 0.562" | 0.290" | 0.015" – 0.250" |
| 5/16" Option | 0.688" | 0.290" | 0.015" – 0.250" |
| 3/8" Standard | 0.625" | 0.355" | 0.015" – 0.250" |
| 3/8" Option | 0.812" | 0.355" | 0.015" – 0.250" |
| 1/2" Standard | 1.062" | 0.490" | 0.015" – 0.250" |
| 3/4" Standard | 1.500" | 0.740" | 0.015" – 0.250" |
Standard RMA Thicknesses and Tolerances for Elastomers
| Nominal Thickness | Tolerance |
|---|---|
| 0.015" | ±0.010" |
| 0.031" | ±0.012" |
| 0.062" | ±0.016" |
| 0.093" | ±0.016" |
| 0.125" | ±0.020" |
| 0.187" | ±0.031" |
| 0.250" | ±0.031" |
| 0.375" | ±0.047" |
| 0.500" | ±0.047" |
Standard references shown. Cannon Gasket also cuts custom outside diameters, inside diameters, and thicknesses to your drawing. Send your specifications for a quote.