Our Chart 50 reflects the 'O' ring standards used in many countries, particularly those of the UK and USA. Despite UK metrification, inch sizes to BS1806 are still very popular.
On Chart 50, the reference numbers highlighted in red indicate those sizes covered by:
BS1806: Dimensions of toroidal seals ('O' rings) and their housing sizes, and
SAE AS568A: American National Standard Aerospace size standard for 'O' rings.
Although the basic range is in inches, the 'O' rings can of course be used for sealing metric dimensioned components. Our Chart 50 tables include suggested metric shaft and cylinder sizes for which each specific 'O' ring is suitable. (Note that these figures are NOT merely direct metric conversions of the inch sizes. Separate ranges of back-up rings are available for metric shafts and cylinders.)
JW Chart 50 'O' rings
