// ASSEMBLY COMPONENTS
O-rings specified by size and compound.
An O-ring size identifies its geometry, but the compound determines which service conditions the seal is intended for. Send Webson the full part designation, including material requirements, or the seal and gland drawings for quotation.
Request an O-ring quote →Pricing and availability confirmed with quotation.
Identify the seal arrangement
On a small screen, scroll sideways to see the full table.
| Component | What it does | What to specify |
|---|---|---|
| Standard-size O-rings | Use a specified size system and its dimensional tolerances. | Full size designation, compound and applicable standard. |
| Metric or drawing-specific rings | Follow the required inside diameter and cross-section. | Dimensions, tolerances, compound and drawing revision. |
| Static sealing arrangements | Seal between surfaces without the specified relative sealing motion. | Gland geometry, media, pressure and temperature requirements. |
| Dynamic sealing arrangements | Operate with the specified relative movement. | Motion, gland details, operating conditions and the approved seal requirement. |
Keep ring dimensions separate from groove dimensions
Inside diameter and cross-section describe the uninstalled O-ring. Groove depth, width and mating clearances describe the gland. Do not use one set of dimensions in place of the other when identifying a replacement.
On a small screen, scroll sideways to see the full table.
| Feature | Information to send | What to check |
|---|---|---|
| Ring size | Inside diameter and cross-section or full standard size code. | Use the specified tolerances and size system. |
| Compound and hardness | Exact material designation and hardness requirement. | Color alone is not a reliable material identifier. |
| Gland | Groove and mating geometry or approved assembly drawing. | Check against the selected seal design requirements. |
| Service conditions | Media, temperature, pressure and motion where applicable. | Compatibility depends on the actual compound and conditions. |
“Rubber” is not a purchasing specification
Include the approved compound and any required certification, cure-date or packaging controls. If the original designation is missing, send the application conditions and available drawings for review. Avoid choosing a replacement solely because its color and dimensions look right.
Replacement seals and production requirements
For established equipment, the approved part list is the best starting point. For a new assembly, provide the seal requirement and gland details. This page helps identify information for quotation; it does not replace the seal design or compatibility review.
Before you order
Does a dash size specify the O-ring material?
The size designation and compound are separate requirements unless a complete specification combines them. Preserve the full purchasing designation.
Can I identify the compound from its color?
Do not rely on color alone. Use the manufacturer’s designation, approved specification or documented material requirement.
Should I measure a stretched or worn ring?
It may help identify a candidate size, but stretching, wear and service exposure can change dimensions. Confirm against the original requirement before ordering.
Quote the size and compound as one requirement
Send the full part number or size, compound, hardness, quantity and delivery date. Include the applicable specification, documentation, packaging and shelf-life controls required by the order.
Request an O-ring quote →Webson is an AS9120B and ISO 9001:2015 certified distributor. Include required certificates and traceability with your inquiry. View our certificate and quality scope.
Webson Fasteners · Serving customers since 1986 · Deer Park, New York