Product Range

KF Fittings


The KF ranges of flanges and fittings are manufactured from high quality stainless steel. KF flanges utilize an aluminium clamp with a single wingnut fastener allowing frequent disassembly without tools.

The vacuum seal is effected by uniform applications of pressure by the clamp on the 15° surface of the flange. The mating flange surfaces compress an ‘O’-ring (held in place by a metal ring) to produce a seal that can used in vacuum applications down to 10-8 mbar and baked to 200°C (sustained to 150°C)

Advanced sealing material such as aluminium or copper may be used, when the joints have to be operated or baked at elevated temperatures or if high corrosion resistance and/or electrical insulation are required.

Our vacuum components are bead-blasted inside and outside, unless otherwise stated. The sealing faces are polished mechanically.

All components are subjected to a leak testing protocol.

KF25 Blank Flange
SKU: KF25BS
KF Flanges (Klien) are the standard din 28430 & ISO 2861 connections for vacuum fittings up to DN50 used in low & high vacuum. Along with the ancillary components they offer a simple solution for applications requiring easy and repeated assembly.Sealing is accomplished with a centering with a nitrile or viton o’ring squashed between a pair of KF Flanges and pulled together using a circumferental clamp.KF Blank Flanges points:Material: 304L stainless steelBakeable to 150° CVacuum Rating: 1×10-8 mbarWide range of elbows, crosses & tees are availableTubulated Flanges are available for welding to stainless steel tubeKF Blank flanges are used to cap off the open ports where not required and are also used as a base part to manufacture adaptor fittings, instruments, feedthroughs etc.Manufactured from: 304 Stainless Steel. KF Blank flanges are supplied in a sealed plastic bag with a protective plastic cap.KF Blank flanges are manufactured to the ISO Standard and are compatible with other supplier’s product.
£ 2.99 2.99 GBP
KF25 Clamp - Aluminium
SKU: KF25C
KF Clamps Aluminium are used to clamp two flanges to a Centering ring and an O Ring creating a vacuum seal.

KF Clamps Aluminium are manufactured from aluminium and are supplied in a sealed plastic bag.

KF Clamps Aluminium are manufactured to the ISO standard and are compatible with other supplier’s products.
£ 3.40 3.4 GBP
KF25 to KF10 Tubulated Reducing Adaptor
SKU: KF25R10
KF Tubulated Reducing Adaptors are used to change the size of a tube or flange from one size to another. This enables mismatched components to be fitted together.Manufactured from: 304 Stainless Steel. Helium Leak tested to 10-8 mbar. KF Tubulated Reducing Adaptors are supplied in a sealed plastic bag with protective plastic caps.KF Tubulated Reducing Adaptors are manufactured to the ISO Standard. They are compatible with other suppliers’ products.
£ 16.65 16.65 GBP
KF25 to KF16 Tubulated Reducing Adaptor
SKU: KF25R16
KF Tubulated Reducing Adaptors are used to change the size of a tube or flange from one size to another. This enables mismatched components to be fitted together.Manufactured from: 304 Stainless Steel. Helium Leak tested to 10-8 mbar. KF Tubulated Reducing Adaptors are supplied in a sealed plastic bag with protective plastic caps.KF Tubulated Reducing Adaptors are manufactured to the ISO Standard. They are compatible with other suppliers’ products.
£ 8.64 8.64 GBP
KF25 Stainless Steel Centering Ring with Viton O-Ring
SKU: KF25SVCR
KF Stainless Steel Centering Rings with Viton O-rings are used to connect two flanges together and create a vacuum seal with the use of a clamp.

Manufactured from 304 stainless steel and Viton. KF Stainless Steel Centering Rings are supplied in a sealed plastic bag.

KF Stainless Steel Centering Rings are manufactured to the ISO standard and are compatible with other supplier’s products
£ 4.95 4.95 GBP
KF25 Stainless Steel Meshed Centering Ring with Viton O-Ring
SKU: KF25SVCRM
KF Stainless Steel Reducing Centering Rings are used to connect two flanges of different internal sizes. This creates a vacuum seal with the use of a clamp.

Manufactured from 304 stainless steel and Viton. KF Stainless Steel Reducing Centering Rings are supplied in a sealed plastic bag.

KF Stainless Steel Reducing Centering Rings are manufactured to the ISO standard and are compatible with other supplier’s products.
£ 18.35 18.35 GBP
KF25 SS Trapped Centre Ring with Viton O-Ring
SKU: KF25SVCRT

KF25 Trapped Centering Ring with Viton O-Ring

KF Trapped Centering Rings with Viton O-rings are used to connect two flanges together and create a vacuum seal with the use of a clamp they also provide for cases of slight over pressure. Manufactured from 304 stainless steel, Aluminium and Viton. KF Trapped Centering Rings are supplied in a sealed plastic bag. KF Trapped Centering Rings are manufactured to the ISO standard and are compatible with other supplier’s products.
£ 5.85 5.8500000000000005 GBP
KF32/40 Stainless Steel Reducing Centering Ring with Viton O-Ring
SKU: KF32/40SVRCR

KF Stainless Steel Reducing Centering Rings are used to connect two flanges of different internal sizes. This creates a vacuum seal with the use of a clamp.

Manufactured from 304 stainless steel and Viton. KF Stainless Steel Reducing Centering Rings are supplied in a sealed plastic bag.

KF Stainless Steel Reducing Centering Rings are manufactured to the ISO standard and are compatible with other supplier’s products.
KF40 Aluminium Centering Ring with Viton O-Ring
SKU: KF40AVCR
KF Aluminium Centering Rings with Viton O Rings are used to connect two flanges together and create a vacuum seal with the use of a clamp.

Manufactured from Aluminium and Viton. KF Aluminium Centering Rings are supplied in a sealed plastic bag.

KF Aluminium Centering Rings are manufactured to the ISO Standard and are compatible with other supplier’s product.
£ 2.99 2.99 GBP
KF40 44mm Bored Flange
SKU: KF40B44
KF Flanges (Klien) are the standard din 28430 & ISO 2861 connections for vacuum fittings up to DN50 used in low & high vacuum. Along with the ancillary components they offer a simple solution for applications requiring easy and repeated assembly.Sealing is accomplished with a centering with a nitrile or viton o’ring squashed between a pair of KF Flanges and pulled together using a circumferental clamp.KF Bored Flanges points:Material: 304L stainless steelBakeable to 150° CVacuum Rating: 1×10-8 mbarWide range of elbows, crosses & tees are availableTubulated Flanges are available for welding to stainless steel tubeKF Bored flanges are used for welding onto tube to produce ports and connectors when manufacturing fabrications.Manufactured from: 304 Stainless Steel. KF Bored flanges are supplied in a sealed plastic bag with a protective plastic cap.KF Bored flanges are manufactured to the ISO Standard and are compatible with other supplier’s product.
£ 6.50 6.5 GBP
KF40 Blank Flange
SKU: KF40BS
KF Flanges (Klien) are the standard din 28430 & ISO 2861 connections for vacuum fittings up to DN50 used in low & high vacuum. Along with the ancillary components they offer a simple solution for applications requiring easy and repeated assembly.Sealing is accomplished with a centering with a nitrile or viton o’ring squashed between a pair of KF Flanges and pulled together using a circumferental clamp.KF Blank Flanges points:Material: 304L stainless steelBakeable to 150° CVacuum Rating: 1×10-8 mbarWide range of elbows, crosses & tees are availableTubulated Flanges are available for welding to stainless steel tubeKF Blank flanges are used to cap off the open ports where not required and are also used as a base part to manufacture adaptor fittings, instruments, feedthroughs etc.Manufactured from: 304 Stainless Steel. KF Blank flanges are supplied in a sealed plastic bag with a protective plastic cap.KF Blank flanges are manufactured to the ISO Standard and are compatible with other supplier’s product.
£ 3.41 3.41 GBP
KF40 Clamp - Aluminium
SKU: KF40C
KF Clamps Aluminium are used to clamp two flanges to a Centering ring and an O Ring creating a vacuum seal.

KF Clamps Aluminium are manufactured from aluminium and are supplied in a sealed plastic bag.

KF Clamps Aluminium are manufactured to the ISO standard and are compatible with other supplier’s products.
£ 2.99 2.99 GBP
KF40 to KF10 Tubulated Reducing Adaptor
SKU: KF40R10
KF Tubulated Reducing Adaptors are used to change the size of a tube or flange from one size to another. This enables mismatched components to be fitted together.Manufactured from: 304 Stainless Steel. Helium Leak tested to 10-8 mbar. KF Tubulated Reducing Adaptors are supplied in a sealed plastic bag with protective plastic caps.KF Tubulated Reducing Adaptors are manufactured to the ISO Standard. They are compatible with other suppliers’ products.
£ 21.60 21.6 GBP
KF40 to KF16 Tubulated Reducing Adaptor
SKU: KF40R16
KF Tubulated Reducing Adaptors are used to change the size of a tube or flange from one size to another. This enables mismatched components to be fitted together.Manufactured from: 304 Stainless Steel. Helium Leak tested to 10-8 mbar. KF Tubulated Reducing Adaptors are supplied in a sealed plastic bag with protective plastic caps.KF Tubulated Reducing Adaptors are manufactured to the ISO Standard. They are compatible with other suppliers’ products.
£ 13.16 13.16 GBP
KF40 to KF25 Tubulated Reducing Adaptor
SKU: KF40R25
KF Tubulated Reducing Adaptors are used to change the size of a tube or flange from one size to another. This enables mismatched components to be fitted together.Manufactured from: 304 Stainless Steel. Helium Leak tested to 10-8 mbar. KF Tubulated Reducing Adaptors are supplied in a sealed plastic bag with protective plastic caps.KF Tubulated Reducing Adaptors are manufactured to the ISO Standard. They are compatible with other suppliers’ products.
£ 19.99 19.990000000000002 GBP
KF40 Stainless Steel Centering Ring with Viton O-Ring
SKU: KF40SVCR
KF Stainless Steel Centering Rings with Viton O-rings are used to connect two flanges together and create a vacuum seal with the use of a clamp.Manufactured from 304 stainless steel and Viton. KF Stainless Steel Centering Rings are supplied in a sealed plastic bag.KF Stainless Steel Centering Rings are manufactured to the ISO standard and are compatible with other supplier’s products
£ 3.99 3.99 GBP
KF40 Stainless Steel Meshed Centering Ring with Viton O-Ring
SKU: KF40SVCRM
KF Stainless Steel Reducing Centering Rings are used to connect two flanges of different internal sizes. This creates a vacuum seal with the use of a clamp.

Manufactured from 304 stainless steel and Viton. KF Stainless Steel Reducing Centering Rings are supplied in a sealed plastic bag.

KF Stainless Steel Reducing Centering Rings are manufactured to the ISO standard and are compatible with other supplier’s products.
£ 24.90 24.900000000000002 GBP
Demountable viewport on a KF40 flange with UV grade fused silica optic
SKU: KF40VPDF

Demountable viewport on a KF40 flange with UV grade fused silica optic

Demountable viewport for high vacuum systems allowing users to change optics without having to replace the complete viewport, which saves money, and is very useful if optic damage is likely, for example, in laser applications

Constructed from stainless steel 304L (1.4307) with an aluminium alloy retainer
Can be installed on standard KF vacuum ports, no special adaptors or fittings needed
UHV cleaned and helium leak tested
Typical lead time 4-6 weeks
Optic materials available: borosilicate glass, sapphire, zinc selenide (ZnSe), magnesium fluoride (MgF2), barium fluoride (BaF2) and calcium fluoride (CaF2). Other materials may be supplied on request.

Different sizes available on request.
£ 280.00 280.0 GBP
Demountable viewport on a KF40 flange with borosilicate glass (Kodial) optic
SKU: KF40VPDK

Demountable viewport on a KF40 flange with borosilicate glass (Kodial) optic

Demountable viewport for high vacuum systems allowing users to change optics without having to replace the complete viewport, which saves money, and is very useful if optic damage is likely, for example, in laser applications

Constructed from stainless steel 304L (1.4307) with an aluminium alloy retainer
Can be installed on standard KF vacuum ports, no special adaptors or fittings needed
UHV cleaned and helium leak tested
Typical lead time 4-6 weeks
Optic materials available: borosilicate glass, sapphire, zinc selenide (ZnSe), magnesium fluoride (MgF2), barium fluoride (BaF2) and calcium fluoride (CaF2). Other materials may be supplied on request.

Different sizes available on request.
£ 270.00 270.0 GBP
KF50 Aluminium Centering Ring with Viton O-Ring
SKU: KF50AVCR
KF Aluminium Centering Rings with Viton O Rings are used to connect two flanges together and create a vacuum seal with the use of a clamp.

Manufactured from Aluminium and Viton. KF Aluminium Centering Rings are supplied in a sealed plastic bag.

KF Aluminium Centering Rings are manufactured to the ISO Standard and are compatible with other supplier’s product.
£ 5.99 5.99 GBP