Custom Size NBR Buna-N O-Rings Molded to AS568 and ISO 3601 Metric Spec
Custom Size NBR Buna-N O-Rings Molded to AS568 and Metric Spec
Custom-size NBR (Buna-N) O-rings are specified for replacement glands, prototype assemblies and dimensions outside standard size series. Provide inner diameter, cross-section and tolerances, together with nominal hardness and service conditions. A removed seal can help identify the part, but worn or swollen sample dimensions must be checked against the mating groove before tooling is agreed.
| Material | NBR (Nitrile / Buna-N) |
|---|---|
| Hardness | 70 / 90 Shore A (other grades on request) |
| Standards | AS568, ISO 3601 (metric), custom |
| Cross-Section | Specify ID and cross-section; OD = ID + 2 × cross-section |
| Temperature | Confirm temperature limits for the selected NBR compound |
| Color | Black (colored compounds available) |
| MOQ | Per inquiry — depends on existing tooling |
Capabilities
- Mold to AS568 dash sizes and ISO 3601 metric dimensions
- Non-standard cross-sections and diameters from drawing or sample
- Specify low-temperature, color or food-contact requirements for compound review
- Review sample dimensions against the gland drawing before reproducing an obsolete seal
Applications
Replacement of discontinued O-rings, hydraulic and pneumatic custom glands, prototype builds, and field repairs where standard dash sizes do not fit.
FAQ
Q: What do you need to make a custom O-ring?
A: Send ID, cross-section and tolerances, or a dimensioned drawing. Include groove dimensions, fluid, pressure, temperature, nominal hardness and quantity. For a sample, identify whether it is new or used so wear, stretch and swelling are considered.
Q: Can you match AS568 and metric sizes exactly?
A: Specify the AS568 dash number or metric dimensions and the required tolerance class. Standard sizes have defined tolerances rather than zero dimensional variation. Custom dimensions and inspection criteria should be agreed on the drawing.
Q: What is the minimum order quantity?
A: MOQ depends on whether tooling already exists. Sizes we already tool can run in smaller batches; a fully new tool carries a setup we quote per inquiry.
Q: How should dimensional tolerances be specified?
A: State the applicable dimensional standard, tolerance class and inspection method. Feasibility of a tighter tolerance must be reviewed for the ring size, compound and tooling; confirm it on the approved drawing.
Q: How long does a custom order take?
A: The quotation should confirm tooling, sample approval and production lead time for your size and quantity. Provide the required delivery date and any inspection or documentation requirements with the inquiry.
Q: Is NBR the right material for my fluid?
A: Provide the exact fluid, additives, concentration and temperature. Review compatibility using the selected compound data. Sour-gas service and food-contact use require application-specific qualification; polymer names alone do not establish suitability.
Get in Touch
Have questions about our products or want to discuss a custom order? Our team is ready to help you.