SealSpec / O-rings
O-rings for production designs
Size, material and groove reference for engineers specifying O-rings, plus a builder that turns your choices into a spec sheet.
AS568 size chart369 sizes with drawingsGroove calculatorSqueeze / stretch / fillFluid compatibility2,088 media × 13 elastomersO-ring spec builderStandard or custom size
By material
| Viton / FKM | FKM fluoroelastomer: the default for fuels, oils, many chemicals and heat (to ~400 °F for standard grades). |
| Nitrile / Buna-N | NBR: the general-purpose choice for petroleum oils, hydraulic fluid and water; weak in ozone/UV and ketones. |
| EPDM | EPDM: water, steam, glycol, brake fluid and outdoor exposure; swells in petroleum oils. |
| Silicone | VMQ: very wide temperature range and food/medical grades; low tear strength, not for dynamic service or fuels. |
| Fluorosilicone | FVMQ: silicone's temperature range with improved fuel and oil resistance; mostly static use. |
| Neoprene | CR: moderate oil and weather resistance; common in refrigeration and general industrial seals. |