حلقات O-Ring من HNBR بقطر داخلي 1.287 بوصة وقطر مقطع 0.21 بوصة | AS568-323 | داش 323 | صلابة 80 (25 / عبوة)

Installed these on a hydraulic fitting that sees some heat cycles, and the HNBR seems to handle it much better than standard Buna-N. The fit was exactly right on a 1.287" groove, no binding or leaks.

The 80 durometer hardness is spot on—they feel firm but not brittle when I stretch them into place. The -40°F rating gives me confidence for my outdoor equipment that sits through harsh winters.

These fit perfectly in the hydraulic valve I was rebuilding—the 80 durometer feels just right for the high-pressure seal. I’ve used cheaper nitrile before, but these HNBR rings seem much more resistant to heat.