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AS568-389

Standard Imperial O-Ring Size

Dimensions

Inside Diameter (inch)6.275 in
Cross Section (inch)0.139 in
Inside Diameter (mm)159.38 mm
Cross Section (mm)3.53 mm
Recommended Groove Depth0.104 in
Theoretical Static Compression25.2% (Target: 15-25%)

Compression Rate Guidance

  • Static seals: 15-25% compression is ideal for most applications.
  • Dynamic seals: 10-20% compression to reduce friction and wear.
  • Groove width should typically be 1.1 to 1.3 times the O-ring cross section.
  • Surface finish: 16-32 microin Ra for static, 8-16 microin Ra for dynamic.

Related Resources

Imperial Size Chart

Browse the full AS568 table when you need adjacent dash numbers or series comparisons.

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Size Converter

Convert this imperial size to metric equivalents before choosing ISO or JIS alternatives.

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Compression Calculator

Check gland squeeze and confirm whether your groove depth matches the target compression range.

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AS568 PDF Download

Request the printable size chart for engineering review, quoting, or shop-floor reference.

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