The CF (ConFlat) flange is the most popular and widely used flange for high vacuum and UHV applications. Many gauges, instruments, accessories, and feedthroughs are available on this system.

This sizing guide will focus on ConFlat fixed flanges. These flanges are a onepiece design where the bolt-hole orientation is fixed with respect to that fitting

Depending on material, ConFlat flanges operate from 760 Torr (1013 mbar) to < 1 x 10-13 Torr (<1.3 x 10-13 mbar), and within the temperature range -321°F to 842°F.