O-Ring Groove Design

How to Design an O'ring Groove

   Use our fully automatic design tool!
Simply select your seal type, then if it will be in a static or dynamic condition and lastly select the size of o'ring you plan on using. Our calculator will do the rest for you by bringing up the industry standard o'ring groove size and calculating all of the relevant groove parameters. After the default is loaded you then have the ability to adjust all of the groove geometry to suit your particular application and immediately see how it affects the grooves operational parameters. This calculator also has bumpers installed to keep impossible dimensions from being entered.

O'ring Groove Design Guidelines

   Proper o-ring groove dimension guidelines have been hashed out by major players in the industry including SAE, Parker, and Trelleborg just to name a few. These large organizations have tested and proven optimal design parameters and provide references for the industry to use as guidelines on proper grove design. For more information from these sources, scroll down to the “standards that apply” and the “tools that apply” list to get detailed information from them directly. Our website has the most common design parameters built in so you don't have to know them or reference them in a table.

What Could Go Wrong With O'rings?

   One common o-ring failure is extrusion. This happens when the pressure against the o-ring is so high that it extrudes out into the gap that it once sealed. This is why it's important to know how much of a gap your design will have and what your o-ring can handle.
   Another common failure is not enough squeeze to hold a seal. We've seen this happen, an engineer specified a dynamic type o-ring groove for a static situation that had really high pressures. This combination of low squeeze and high pressure resulted in the o-ring not being able to hold the pressure. The solution was to swap to a harder o-ring, and to include a better backup ring to help reduce the gap that the o-ring sees. This swap worked perfectly, but time would have been saved if the o-ring groove was specified correctly from the get go as static.

Parameter Definition

Groove ID Max & Groove ID Min

This parameter will be the smallest diameter that the o-ring touches.

Bore Dia Max & Bore Dia Min

This parameter will be the largest diameter that the o-ring touches.

Groove Width Max & Groove Width Min

This will be the linear axial distance of the first two parameters. (perpendicular, at 90°)

ID Stretch % Min & ID Stretch % Max

This is how much the inside of the o-ring is stretched. For internal face seals this will change over to how much the OD is compressed.

Compression % Min & Compression % Max

This is the amount of squeeze the cross section of the o-ring sees. This calculation accounts for changes in cross section due to stretching of the oring.

Gland Fill % Min & Gland Fill % Max

This is what percent of the groove volume does the o-ring occupy.

O-Ring Id Min & O-Ring Id Max

This is the inner diameter of the o-ring.

O-Ring Cross-Section Min & O-Ring Cross-Section Max

This is how thick the o-ring is.

Helpful Resources and References

Standards That Apply

These are the industry standard for O-ring Groove Design:
ISO 3601-1:2012
SAE AS4716 Dynamic & Static
SAE AS5857 Static Only, Higher Squeeze
SAE AS6235 Face Seals
Parker O-Ring Handbook ORD 5700
ERIKS Sealing Elements - Technical Handbook O-rings

Tools That Apply

Try out these O-ring groove design apps:
Parker O-Ring Selector
Trelleborg AeroGlands AS4716 & AS5857
Trelleborg AeroGlands AS4716
Trelleborg AeroGlands AS4716
Trelleborg AeroGlands AS6235
Trelleborg O-Ring Calculator