KEVOS® MAKEOS · Engineering
O-Ring Squeeze, Stretch and Gland Fill
Will this O-ring have the right squeeze, stretch and gland fill in this groove?
Squeeze, stretch (or circumferential compression), reduced cross-section and gland fill of an O-ring in a piston (male) or rod/bore (female) groove, compared with typical design ranges.
Open the calculatorRuns in your browser. No account needed.
How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Groove location | choice | Piston (male) grooves stretch the ring; rod (female) grooves compress it circumferentially. |
| Duty | choice | Static seals tolerate more squeeze than dynamic seals. |
| O-ring inside diameter | mm | Inside diameter of the O-ring from the size standard (e.g. AS 568 or ISO 3601). |
| O-ring cross-section | mm | Cross-section diameter of the O-ring. |
| Groove diameter (bottom for piston, outer for rod) | mm | Piston groove bottom diameter, or rod/bore groove outer diameter. |
| Gland depth (groove bottom to mating surface) | mm | Radial distance from the groove bottom to the mating surface, at nominal clearance. |
| Groove width | mm | Axial width of the groove. |
Method and formulas
- Piston: stretch = (groove diameter − ring ID) ÷ ring ID. Rod: compression = (ring OD − groove diameter) ÷ ring OD.
- Stretched cross-section ≈ CS ÷ √(1 + stretch) (constant volume).
- Squeeze = (CS′ − depth) ÷ CS′; fill = (π CS′² ÷ 4) ÷ (depth × width).
- Example: a 47.22 × 2.62 ring in the default piston groove has 1.6518% stretch, 19.188% squeeze and 70.154% fill.
Limitations
- Nominal dimensions; repeat at tolerance extremes and with swell in the working fluid.
- Typical ranges used for the checks vary by seal maker and application; confirm with the seal supplier.
- Example values are illustrations. Replace them with values for your actual task.
Typical uses
- Check a groove design before release
- Choose an O-ring size for an existing groove
- Investigate a leaking or extruding seal
Who it is for
- Design engineers
- Maintenance engineers
What you get
- Stretch or circumferential compression
- Cross-section after stretch
- Squeeze
- Gland fill
Interpreting the result
- Typical guidance: static squeeze about 15–30%, dynamic about 10–20%, fill below about 85%, stretch up to about 5%.
References
- Machinery’s Handbook, 29th edition (Industrial Press, 2012), printed pp. 2591–2610. Topic reference; no source tables or recommended settings are reproduced.
- ISO 3601-2 Fluid power systems — O-rings — Housing dimensions for general applications
WORKOS tools are screening and decision-support utilities. Verify important financial, engineering, safety, legal or operational decisions using appropriate professional standards and your organisation’s approved data.
