O-Ring Calculator

O-Ring Calculator

Check squeeze, stretch and gland fill for common gland styles. Units: mm or inches.

Nominal cross-section of the O-ring.
Free-state ID of the O-ring.
For Rod: shaft diameter. For Axial: mean groove diameter.
For Piston: bore diameter. For Axial: mating cover diameter.
Axial width of the gland groove.
Radial groove depth (from surface to groove base).
Results
Values shown in selected units. Guidelines are general—verify for your material and service.
Squeeze (Compression)
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Target ranges vary by application.
Installed Stretch
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Stretch on ID (rod/axial) or on OD (piston).
Gland Fill
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Typically keep below ~85% static / ~80% dynamic.
Guideline ranges (typical, not absolute):
  • Static radial/axial squeeze: ~10–30%
  • Dynamic squeeze (reciprocating): ~8–16%
  • Installed stretch: ~1–5% (static), ~2–5% (dynamic). Avoid >8–10%.
  • Gland fill: ≤ ~85% (static), ≤ ~80% (dynamic), allowing swell & thermal expansion.