There are several specifications available for hardware and gland dimensions.  Some of the more widely used are:

SAE AS4716 - Aerospace Standard, Gland Design, O-Ring and Other Elastomeric Seals

SAE AS5857 - Gland Design, O-rings and Other Elastomer Seals, Static Applications

SAE ARP1231 - Gland Design, Elastomeric O-Ring Seals, General Considerations

ISO 3601-2 - Fluid power system - O-rings - Part 2: Housing dimensions for general applications

While these specifications are good starting points to help determine what seal size you need or what your hardware dimensions should be, we recommend determining the actual seal fit.  You should also take your performance requirements into consideration. Not every seal-hardware combination listed in these specifications has optimal seal fit and therefore, may not give the performance you require for your specific application. 

For an evaluation of your specific application and seal fit, please contact us either by e-mail ( This e-mail address is being protected from spambots. You need JavaScript enabled to view it ) or by filling out the Engineering / Technical Request form on this site (click here for the form).