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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
Essentials of Manufacturing

Information, coverage of important developments and expert commentary in manufacturing.

Selecting the Right 3D Printer

Discover how to choose the right 3D printer for your needs and the key performance attributes to consider.

CNC Machining Design Guide

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

STEM Career Outlook

Wages, employment opportunities, and growth projections for STEM jobs.