got a -256 o-ring groove, is this back-up ring meant to match that dash size or am i mixing things up
Question by: Ray G on Mar 18, 2026, 10:33 AM
Sizes correspond to O-ring sizes, so the -256 back-up ring is intended to go with a -256 O-ring size.
Answer by: Customer Support on Mar 20, 2026, 6:33 AM
How flexible are these backup rings? I'm worried about getting them installed without damaging them.
Question by: Travis W on Apr 24, 2025, 9:08 AM
Molded from a 90A durometer urethane, these rings offer some give to help with installation, expanding as needed and then returning to their original size.
Answer by: Customer Support on Apr 25, 2025, 2:56 PM
these stretch for install and snap back into shape -- how hard is that to actually do in the field, and will they hold their size after?
Question by: Brett W on Feb 8, 2026, 7:38 PM
Urethane at 90A durometer has enough flexibility to stretch over a groove without cracking or permanently deforming. Once seated, the material rebounds to its molded dimensions pretty reliably. That memory is actually one of the reasons urethane gets spec'd for back-up rings over stiffer materials in applications where quick field installation matters. You shouldn't need any special tooling, just careful handling to avoid nicking the ring on sharp edges during installation.
Answer by: Customer Support on Feb 10, 2026, 2:25 PM
these stretch for install and snap back into place? trying to figure out if i need any special tools or if they just go on by hand
Question by: Connie W on Oct 29, 2025, 4:55 PM
Hand installation is the standard approach for these. The urethane material is flexible enough to stretch over the fitting or groove, then it returns to its original shape once seated. No special tooling required in most cases. The 90A durometer keeps them firm enough to resist extrusion while still giving you that flexibility during install.
Answer by: Customer Support on Oct 31, 2025, 1:42 PM
