The KF (QF) flange is used for through- or foreline vacuum plumbing and for simple HV chamber ports.
KF flanges are a sexless design—made from 304L and 316L stainless, aluminum, or brass. Stainless steel flanges work in adverse temperatures and corrosive conditions, while aluminum or brass fittings work in more general applications.
The seal is a rubber/ elastomeric o-ring mounted in a centering ring, which aligns the flanges and holds the o-ring in position.
Each flange has a chamfered back-surface and is mated by a circumferential clamp tightened by wing-nut, thumbscrew, bolt, or over-center lever.
KF flanges are limited (by the o-ring's properties) to applications with temperatures between ~0° C and 120–180° C, and pressure from atmosphere to ~10-8 torr or mbar.
All dimensions listed in the table below, unless otherwise stated, are in inches.
All dimensions listed in the table below, unless otherwise stated, are in millimeters.