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Weld Ring KF (QF) Flanges (304L SS)

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.

ISO Standard Our KF Flanges are compatible to the ISO Standard 2861 Specification.

Contact Us
To speak with someone directly, please call +1 412 387 9200 or email international@lesker.com.
Note:
  • These flanges are identical to the ISO NW flange standard. While these flanges are compatible with those made by European manufacturers, the tube diameter listed is in inches.

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Ordering Table

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Flange Selection Guide
With a variety of flanges to choose from, the Flange Selection Guide is designed to help you find one to meet your vacuum requirements. Shop Now!
Can't find the flange you need or want a custom configuration? Please call us at +1 412 387 9200 or email international@lesker.com with your inquiry.

Accessories Table

Description For Per Package
VacuCADSM
Part Number Price In Stock Add Item
Description For Per Package
VacuCADSM
Part Number Price In Stock Add Item
Cast Clamps (Aluminum) KF10, KF16 Flanges 1
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QF16-075-C
P.O.R. In Stock
Cast Clamps (SS) KF10, KF16 Flanges 1
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QF16-075-CS
$46.25 In Stock
Cast Clamps (Aluminum) KF25 Flanges 1
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QF25-100-C
P.O.R. In Stock
Cast Clamps (SS) KF25 Flanges 1
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QF25-100-CS
$57.30 In Stock
Cast Clamps (Aluminum) KF40 Flanges 1
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QF40-150-C
P.O.R. In Stock
Cast Clamps (SS) KF40 Flanges 1
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QF40-150-CS
$67.35 In Stock
Cast Clamps (Aluminum) KF50 Flanges 1
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QF50-200-C
P.O.R. In Stock
Cast Clamps (SS) KF50 Flanges 1
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QF50-200-CS
$79.40 In Stock
Lever Clamps (Aluminum) KF10, KF16 Flanges 1
N/A
QF16-075-CHA
$33.20 In Stock
Lever Clamps (Aluminum) KF25 Flanges 1
N/A
QF25-100-CHA
$46.25 In Stock
Lever Clamps (Aluminum) KF40 Flanges 1
N/A
QF40-150-CHA
$54.72 In Stock
Centering Ring (SS with Fluorocarbon O-Ring) KF10 Flanges 1
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QF10-050-SRV
$6.45 In Stock
Centering Ring (SS with Fluorocarbon O-Ring) KF16 Flanges 1
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QF16-075-SRV
$6.75 In Stock
Centering Ring (SS with Fluorocarbon O-Ring) KF25 Flanges 1
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QF25-100-SRV
$8.55 In Stock
Centering Ring (SS with Fluorocarbon O-Ring) KF40 Flanges 1
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QF40-150-SRV
$13.10 In Stock
Centering Ring (SS with Fluorocarbon O-Ring) KF50 Flanges 1
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QF50-200-SRV
$15.10 In Stock