حلقات O من مطاط بونا-نايترايل CS 0.139 بوصة × ID 1.609 بوصة | AS568-223 | داش 223 | مقطع مربع | صلابة 70 (200 / عبوة)

I needed o-rings that could handle both hot oil and cold starts without cracking, and these Buna-N ones have been perfect so far. The 70 durometer feels firm but not brittle, and the square profile kept them from rolling out of the groove during assembly.

The square profile seats better in my worn groove than round ones usually do, and the 70 durometer feels firm without being brittle. I used about 30 of them resealing a hydraulic manifold and none have leaked so far.

These will handle the heat range fine, so I'm using them in a hydraulic setup that gets close to 200 degrees. The 70 durometer gives just enough give to seat without feeling flimsy, and the square profile really locks them into the groove.