حلقات O-Ring من PTFE بقطر داخلي 0.139" × 3.734" | AS568-240 | داش 240 | صلابة 24 (10 / عبوة)

I was worried about getting a good seal under high heat, but these PTFE rings held up perfectly at 450°F in my furnace. The 0.139" cross-section feels substantial and didn't deform at all.

The -350°F lower limit is perfect for our liquid nitrogen handling setup, and they fit the groove precisely without any binding. Out of 10, all sealed on the first try with no leaks visible under UV dye.

Installed these in a high-temp pneumatic application where standard rubber seals were failing weekly. The PTFE handles the 400°F cycles perfectly, and the 24 durometer gives just enough compliance to seal without being too stiff.