ISO Vacuum Fittings Overview
The ISO range of fittings and flanges are manufactured from stainless steel to a high quality.
Fig 2 shows all the configurations; using wall clamps, double claw clamps or bolts tightening together two flanges onto an ‘O’ ring seal (made of Nitrile or Viton) held in place by a centering ring.
There are various types of ISO flanges:
- ISO-K (clamp) flanges with a grooved ring for inserting wall clamps and double claw clamps are smaller and less expensive.
- ISO-F ( fixed) flanges with a set of through-bore holes are pressed together with Nuts and Bolts. They are more stable than ISO-K flanges which enable them to mechanically support parts of the vacuum chamber.
- ISO bolt rings are used to make an ISO-K flange into rotatable ISO-F flanges.
Material: Stainless steel 304L Bakeable to 200’C (150’C continuous) Vacuum rating 1×10-8mbar
Wide range of Crosses , Elbows & Tees are available
Bored Flanges For Welding To Stainless Steel Tube

NW of the flange |
no. of required clamps |
NW 63 |
4 |
NW 80 |
4 |
NW 100 |
4 |
NW 160 |
4 |
NW 200 |
6 |
NW 250 |
6 |
NW 320 |
8 |
NW 400 |
8 |
NW 500 |
12 |
NW 630 |
12 |
- ISO-K flange fixed to vacuum chamber using wall clamps
- ISO-K flange fixed to ISO-F flange using wall clamps, nuts and washers
- . Two ISO-K flanges fixed together using double claw clamps, which is the most commonly used configuration
- ISO-F flange fixed to vacuum chamber using bolts, washers and tapped blind holes
- ISO-K flange fixed to ISO-F flange using bolt rings, bolts, nuts and washers
- Two ISO-F flanges fixed together using bolts, nuts and washers