How to Identify and Measure Fittings
Pipe size is an industry designation, not the actual size. View information about how to measure threaded and unthreaded pipe and pipe fittings.
More
Through-Wall Fittings for High-Vacuum Chambers
- For Use With: See table
- Environment Temperature Range: 32° to 300° F
- Process Temperature Range: -325° to 995° F
- Tubing: Use with 304/304L or 316/316L stainless steel
- Specifications Met: See table
Transfer liquids and gasses into high-vacuum chambers with these assembled fittings, also known as feedthroughs. Because they form a tight seal on chamber walls, they are often used in coating, cooling, and leak-testing applications where negative pressure (vacuum) must be maintained. These fittings are ready to install and include high-vacuum fittings, metal tubing, and Yor-lok tube fittings. On each end, the Yor-lok fittings include a nut and two sleeves that grip your system’s stainless steel tubing. The entire assembly is stainless steel, so it resists rusting. These fittings are not for use in pressure applications.
Quick-clamp fittings meet ISO 2861, which specifies the dimensions of quick-clamp high-vacuum fittings, clamps, and rings to ensure vacuum tightness. These fittings require a clamp and ring (each sold separately) to complete the connection.
Flanged fittings require a gasket and bolt kit (each sold separately) to complete the connection.
For technical drawings and 3-D models, click on a part number.


For Tube | |||||||||
---|---|---|---|---|---|---|---|---|---|
Flange OD | High-Vacuum Flange Size | OD | Wall Thick. | Lg. | Max. Vacuum | Material | Specifications Met | Each | |
For Use With Acetone, Air, Ammonium Hydroxide, Helium, Methane, Nitrogen, Oil, Water | |||||||||
1.18" | 16 | 1/4" | 0.028"-0.095" | 8" | 1 × 10 -8 torr @ 72° F | 304 Stainless Steel | ISO 2861 | 0000000 | 0000000 |
1.57" | 25 | 1/4" | 0.028"-0.095" | 8" | 1 × 10 -8 torr @ 72° F | 304 Stainless Steel | ISO 2861 | 0000000 | 000000 |
2.16" | 40 | 1/4" | 0.028"-0.095" | 8" | 1 × 10 -8 torr @ 72° F | 304 Stainless Steel | ISO 2861 | 0000000 | 000000 |
2.95" | 50 | 1/4" | 0.028"-0.095" | 8" | 1 × 10 -8 torr @ 72° F | 304 Stainless Steel | ISO 2861 | 0000000 | 000000 |


Bolt Hole | For Tube | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Flange OD | High-Vacuum Flange Size | Bolt Circle Dia. | Dia. | No. of | OD | Wall Thick. | Lg. | Max. Vacuum | Material | Each | |
For Use With Acetone, Air, Ammonium Hydroxide, Helium, Methane, Nitrogen, Oil, Water | |||||||||||
1 21/64" | 16 | 1 1/16" | 11/64" | 6 | 1/4" | 0.028"-0.095" | 8" | 1 × 10 -13 torr @ 72° F | 304 Stainless Steel | 0000000 | 0000000 |
2 3/4" | 40 | 2 5/16" | 17/64" | 6 | 1/4" | 0.028"-0.095" | 8" | 1 × 10 -13 torr @ 72° F | 304 Stainless Steel | 0000000 | 000000 |

Material | ||||||
---|---|---|---|---|---|---|
For Flange OD | For High-Vacuum Flange Size | O-Ring | Inner Ring | Max. Vacuum | Each | |
1.18" | 16 | Fluoroelastomer Rubber | 304 Stainless Steel | 1 × 10 -7 torr @ 72° F | 00000000 | 00000 |
1.57" | 25 | Fluoroelastomer Rubber | 304 Stainless Steel | 1 × 10 -7 torr @ 72° F | 0000000 | 00000 |
2.16" | 40 | Fluoroelastomer Rubber | 304 Stainless Steel | 1 × 10 -7 torr @ 72° F | 0000000 | 00000 |
2.95" | 50 | Fluoroelastomer Rubber | 304 Stainless Steel | 1 × 10 -7 torr @ 72° F | 0000000 | 00000 |
Ultra-High-Polish Gasket Fittings for Stainless Steel Tubing

- For Use With: Ammonia, Argon, Butane, Carbon Dioxide, Chloride, Fluoride, Fluorocarbon, Germane, Halide, Helium, Hydrogen, Krypton, Laser Gas, Natural Gas, Neon, Nitrogen, Oxygen, Silane, Sulfur Hexafluoride, Tungsten Hexafluoride, Xenon
- Temperature Range: -420° to 1000° F
- Tubing: Use with 316/316L stainless steel
- Compatible With: Swagelok® VCR
Polished to at least a 15 Ra finish on the inside, these fittings have an ultra-smooth interior surface that helps prevent contamination. Also known as ultra-high-purity fittings, they’re packed in a Class 100 clean room, cleaned, and double bagged. They are commonly used in semiconductor applications. Fittings use a metal gasket (sold separately), which generates fewer particles than a rubber gasket and creates a strong seal in high-pressure and high-vacuum applications. Fittings are 316 stainless steel for excellent corrosion resistance.
To assemble, place a gasket between the gasket ends before gently rotating the female-threaded fitting onto the male-threaded fitting. Tighten until 1/8 of a turn past finger tight.
For technical drawings and 3-D models, click on a part number.

Through-wall fittings mount through your wall or panel to create an inlet or outlet. They’re also known as bulkhead couplings and panel-mount couplings.
For Tube OD | Material | Max. Pressure | Max. Vacuum | Interior Smoothness, Ra | Environmental Rating | Each | |
1/4" | 316L Stainless Steel | 5,100 psi @ 72° F | 10 -11 torr @ 72° F | 5 | Fed. Std. Class 100 | 00000000 | 000000 |


For Tube OD | Nut Material | Max. Pressure | Max. Vacuum | Lg. | Each | |
Male | ||||||
---|---|---|---|---|---|---|
1/4" | 316L Stainless Steel | 5,100 psi @ 72° F | 10 -11 torr @ 72° F | 17/32" | 00000000 | 00000 |
1/4" | 316L Stainless Steel | 5,100 psi @ 72° F | 10 -11 torr @ 72° F | 23/32" | 0000000 | 0000 |
Female | ||||||
1/4" | 316L Stainless Steel | 5,100 psi @ 72° F | 10 -11 torr @ 72° F | 13/16" | 0000000 | 0000 |


Retaining
Tabs
Nickel gaskets are softer than stainless steel gaskets, so they won’t wear down sealing surfaces as much, and they’re easier to tighten. They’re reactive to carbon monoxide and ozone, so they shouldn’t be used with those chemicals.
Hard and heat resistant, stainless steel gaskets can be used in a wider range of applications than nickel gaskets such as carbon monoxide and ozone. However, they’re harder to tighten than nickel gaskets, and they’ll wear down sealing surfaces more quickly.
Silver-plated stainless steel gaskets are softer than unfinished stainless steel gaskets, so they won’t wear down sealing surfaces as much, and they’re easier to tighten. However, they oxidize when exposed to air, and silver particles might flake off during assembly.
Gaskets with retaining tabs stay in place during installation, so you don’t have to hold the gasket while fastening fittings together. This also means they’re less likely to scratch or nick your fittings by rotating during installation.
For Tube OD | Max. Vacuum | Environmental Rating | Each | |
Nickel Gasket | ||||
---|---|---|---|---|
1/4" | 10 -11 torr @ 72° F | Fed. Std. Class 100 | 00000000 | 00000 |
316L Stainless Steel Gasket | ||||
1/4" | 10 -11 torr @ 72° F | Fed. Std. Class 100 | 0000000 | 0000 |
Silver-Plated 316L Stainless Steel Gasket | ||||
1/4" | 10 -11 torr @ 72° F | Fed. Std. Class 100 | 00000000 | 0000 |
316L Stainless Steel Gasket with Retaining Tabs | ||||
1/4" | 10 -11 torr @ 72° F | Fed. Std. Class 100 | 00000000 | 0000 |