Design Home
O-Rings
Overview
Design Guidelines
AS 568A Std Sizes
Chemical Resistance
Calculator
Radial O-Ring Selector
Resources
Bibliography
Autonomous Vehicle Engineering

The No. 1 media source for those developing the next generation mobility solutions.

Metal 3D Printing Design Guide

Direct Metal Laser Sintering (DMLS) 3D printing for parts with reduced cost and little waste.

Wind Systems

Towers, turbines, gearboxes; processes for shaping and finishing component parts.

CNC Machining Design Guide

Optimize your designs, reduce machining time, and lower your costs.

more free magazines

Materials

Design

Processes

Units

Formulas

Math
Calculator Introduction
This calculator allows you to find the recommended O-Ring inner diameter and range of cross section diameters that will fit a given gland size and tolerance range in a radial seal.
Inputs
  Bore diameter, Bd:    
  Bore Tolerance, Btol:    
  Groove Diameter, Gd:    
  Groove Tolerance, Gtol:    
  O-Ring maximum compression, Cmax:     %
  O-Ring minimum compression, Cmin:     %
  O-Ring cross-section diameter tolerance, CStol:    
Answers
  Max. cross-section diameter (excl. tol.), CSmax:  0.068  in
  Min. cross-section diameter (excl. tol.), CSmin:  0.065  in
  Your input CS tolerance, CStol:  0.003  in
  Industry-recommended CS tolerance:  0.003  in
  Recommended O-Ring inner diameter, IDrec:  0.392  in
  Suggested groove width, GW:  0.103  in
 
Equations Behind the Calculator
This calculator implements the following two equations to determine the bounds on the cross-section diameter CS,

The recommended tolerance is based on the cross-section diameter, and is found from the following table:

Cross Section Diameter
(inch)		 Recommended Tolerance
(inch)
CS < 0.104 0.003
0.104 < CS < 0.139 0.004
0.139 < CS < 0.210 0.005
0.210 < CS < 0.275 0.006
0.275 < CS 0.008
The recommended inner diameter is found by stretching the O-Ring circumference by 2% over the minimum Groove Diameter,

The suggested groove width follows from,

More information is provided on the Design Guideline page.

Glossary