Which o-ring standards does Sealparts supply?

AS568, ISO 3601, DIN 3771, BS 1806, BS 4518, JIS B 2401 and NF T47-501, plus metric tooling sizes outside the published standards.

How do I choose an o-ring material?

Start with the fluid, then temperature, then pressure and motion. NBR suits general mineral oil, EPDM water and brake fluid, FKM fuels and high temperature, and FFKM aggressive chemical service.

Do you supply WRAS, KTW, NSF 61 and FDA approved o-rings?

Yes. Approved NBR, EPDM, HNBR, FKM and VMQ compounds are listed for water, gas, food and pharmaceutical duty on our approvals page.

How quickly can you quote o-rings?

Quotations are normally returned within 1–3 working days, priced in GBP, EUR, USD or JPY.

O-Rings — reference & enquiry

Every major o-ring standard.

Elastomer picking. Chemical compatibility.

A working reference for engineers specifying o-rings — 2,611 sizes across nine international standards, 21 elastomers with temperature and chemical profiles, and a 1,099-row compatibility matrix. Add sizes as you browse and we’ll quote them in your currency.

O-rings supplied in the UK

Sealparts supplies o-rings to UK industry across AS568, ISO 3601, DIN 3771, BS 1806, BS 4518, JIS B 2401 and NF T47-501 size systems, together with metric tooling sizes that fall outside the published standards. Sizes run from a 1 mm inside diameter to large-bore rings for hydraulic and process equipment.

Compounds cover NBR, HNBR, EPDM, FKM, FFKM, VMQ, FVMQ, CR, AU and PTFE-based grades. Where the duty is water, gas, food or pharmaceutical, use the approved compound list for WRAS, KTW, ACS, NSF 61, DVGW, FDA, USP and 3-A grades, and check the fluid against the chemical compatibility matrix before you commit to a material.

Japanese equipment usually needs JIS B 2401 P, G, S, SS and V series o-rings, which are not dimensionally interchangeable with AS568. Send the sizes and material to our enquiry page and we will normally quote within 1–3 working days.

8,018 combinations

O-Ring Tooling and Sizes

Search available o-rings by size, material and compound — NBR, EPDM, FKM, HNBR, VMQ, food, gas, WRAS grades.

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2,611 rows

Standard Sizes

Filter by standard, inside diameter and cross-section. mm / inch toggle. Add rows to an enquiry.

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21 elastomers

Materials

NBR, HNBR, EPDM, FKM, FFKM, VMQ, FVMQ, urethanes and more — temperature range and application notes.

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NOK JIS B 2401

Japanese

Dedicated NOK section — JIS P / G / S / SS / V series, AS568, WEX, BE, Iron Rubber and SP-coated o-rings. Full catalogue PDF.

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1,099 chemicals

Compatibility

Search a chemical, see rated volume-swell behaviour across every common elastomer.

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Water · Gas · Food · Pharma

Approvals

Approved compounds across NBR, EPDM, HNBR, FKM and VMQ — WRAS, KTW, ACS, NSF 61, DVGW, FDA, USP, 3-A.

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Quote in GBP / EUR / USD / JPY

Enquiry

Send the sizes you need and tell us the elastomer, quantity and delivery country.

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Standards covered

AS568

SAE Aerospace Size Standard for O-Rings. The most commonly used o-ring standard in the US across aerospace, automotive and general industry.

ISO 3601 G

ISO 3601-1 General-purpose sizes. International standard, metric.

ISO 3601 A

ISO 3601-1 Aerospace sizes with tighter tolerances.

DIN 3771

German Institute for Standardization o-ring dimensions. Very similar to ISO 3601, uses grade specification (N / S) rather than application type.

BS 4518

British Standard metric o-ring dimensions.

BS 1806

British Standard imperial o-ring dimensions. Widely used across UK fluid-power equipment.

JIS B 2401

Japanese Industrial Standard covering P (motion), G (fixed), V (vacuum) and S (fixed) o-rings.

NF T47-501 G

French standard, general-purpose sizes.

NF T47-501 A

French standard, aerospace sizes.