Measure your pipe and fittings to identify their pipe size, thread size, schedule, and thread type. Then, find compatible components.
Bolt-Together High-Vacuum Fittings for Stainless Steel Tubing

For high-vacuum systems with tube sizes too large for quick-clamp (KF) fittings, choose these bolt-together fittings. Also known as ISO-F flanges, they work with tube sizes starting at 2 1/2" OD. Not for use in pressure applications.
To complete the bolt-end connection, you'll need a ring and a bolt kit (both sold separately).

Adapter, Tube ×
Socket-Connect Tube
Adapters | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Bolt Holes | Bolt Kits | ||||||||||||||
| For Tube OD | Flange OD | High-Vacuum Flange Size | Socket Dp. | High Vacuum Connection Type | Material | Max. Vacuum | Bolt Circle Dia. | Dia. | No. of | For Bolt Dia. | Bolts Included | Each | Each | ||
| 2 1/2" | 5.12" | 63 | 1/4" | ISO-F | 304 Stainless Steel | 10 -8 torr @ 72° F | 4 21/64" | 23/64" | 4 | 5/16" | No | 3702N15 | 000000 | 3702N23 | 000000 |
| 3" | 5.71" | 80 | 1/4" | ISO-F | 304 Stainless Steel | 10 -8 torr @ 72° F | 4 59/64" | 23/64" | 8 | 5/16" | No | 3702N16 | 000000 | 3702N24 | 00000 |
| 4" | 6 1/2" | 100 | 1/4" | ISO-F | 304 Stainless Steel | 10 -8 torr @ 72° F | 5 45/64" | 23/64" | 8 | 5/16" | No | 3702N17 | 000000 | 3702N25 | 00000 |
| 6" | 8.86" | 160 | 1/4" | ISO-F | 304 Stainless Steel | 10 -8 torr @ 72° F | 7 7/8" | 7/16" | 8 | 3/8" | No | 3702N18 | 000000 | 3702N26 | 00000 |

Adapters | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Bolt Holes | Bolt Kits | ||||||||||||||
| For Tube OD | Flange OD | High-Vacuum Flange Size | Wall Thick. | High Vacuum Connection Type | Material | Max. Vacuum | Bolt Circle Dia. | Dia. | No. of | For Bolt Dia. | Bolts Included | Each | Each | ||
| 2 1/2" | 5.12" | 63 | 0.065" | ISO-F | 304 Stainless Steel | 10 -8 torr @ 72° F | 4 21/64" | 23/64" | 4 | 5/16" | No | 3702N19 | 0000000 | 3702N23 | 000000 |
| 3" | 5.71" | 80 | 0.065" | ISO-F | 304 Stainless Steel | 10 -8 torr @ 72° F | 4 59/64" | 23/64" | 8 | 5/16" | No | 3702N2 | 000000 | 3702N24 | 00000 |
| 4" | 6 1/2" | 100 | 0.083" | ISO-F | 304 Stainless Steel | 10 -8 torr @ 72° F | 5 45/64" | 23/64" | 8 | 5/16" | No | 3702N21 | 000000 | 3702N25 | 00000 |
| 6" | 8.86" | 160 | 0.109" | ISO-F | 304 Stainless Steel | 10 -8 torr @ 72° F | 7 7/8" | 7/16" | 8 | 3/8" | No | 3702N22 | 000000 | 3702N26 | 00000 |

Caps | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Bolt Holes | Bolt Kits | |||||||||||||
| For Tube OD | Flange OD | High-Vacuum Flange Size | High Vacuum Connection Type | Material | Max. Vacuum | Bolt Circle Dia. | Dia. | No. of | For Bolt Dia. | Bolts Included | Each | Each | ||
| 2 1/2" | 5.12" | 63 | ISO-F | 304 Stainless Steel | 10 -8 torr @ 72° F | 4 21/64" | 23/64" | 4 | 5/16" | No | 3702N11 | 000000 | 3702N23 | 000000 |
| 3" | 5.71" | 80 | ISO-F | 304 Stainless Steel | 10 -8 torr @ 72° F | 4 59/64" | 23/64" | 8 | 5/16" | No | 3702N12 | 000000 | 3702N24 | 00000 |
| 4" | 6 1/2" | 100 | ISO-F | 304 Stainless Steel | 10 -8 torr @ 72° F | 5 45/64" | 23/64" | 8 | 5/16" | No | 3702N13 | 000000 | 3702N25 | 00000 |
| 6" | 8.86" | 160 | ISO-F | 304 Stainless Steel | 10 -8 torr @ 72° F | 7 7/8" | 7/16" | 8 | 3/8" | No | 3702N14 | 000000 | 3702N26 | 00000 |

Flanged Connection | Material | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| For Tube OD | For Flange OD | For High-Vacuum Flange Size | High Vacuum Connection Type | O-Ring | Inner Ring | Max. Vacuum | Max. Temp., °F | Each | |
| 2 1/2" | 5.12" | 63 | ISO-F | Viton® Fluoroelastomer Rubber | 304 Stainless Steel | 10 -8 torr @ 72° F | 400° | 3705N19 | 000000 |
| 3" | 5.71" | 80 | ISO-F | Viton® Fluoroelastomer Rubber | 304 Stainless Steel | 10 -8 torr @ 72° F | 400° | 3705N2 | 00000 |
| 4" | 6.5" | 100 | ISO-F | Viton® Fluoroelastomer Rubber | 304 Stainless Steel | 10 -8 torr @ 72° F | 400° | 3705N21 | 00000 |
| 6" | 8.86" | 160 | ISO-F | Viton® Fluoroelastomer Rubber | 304 Stainless Steel | 10 -8 torr @ 72° F | 400° | 3705N22 | 00000 |
Rings for Claw-Clamp and Bolt-Together
High-Vacuum Fittings for Stainless Steel Tubing



- For Use With: Air
- Max. Temperature: 400° F
- Tubing: Use with 304/304L Stainless Steel or 316/316L Stainless Steel
Create airtight seals in high-vacuum systems by placing these rings between two claw-clamp (ISO-K) or bolt-together (ISO-F) fittings. They contain a Viton® fluoroelastomer O-ring—when you clamp or bolt your fittings together, the O-ring compresses to establish the seal.
Claw-Clamp Connection | Flanged Connection | Material | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| For Tube OD | For Flange OD | For High-Vacuum Flange Size | High Vacuum Connection Type | For Tube OD | For Flange OD | For High-Vacuum Flange Size | High Vacuum Connection Type | O-Ring | Inner Ring | Max. Vacuum | Each | |
| 2 1/2" | 3.74" | 63 | ISO-K | 2 1/2" | 5.12" | 63 | ISO-F | Viton® Fluoroelastomer Rubber | 304 Stainless Steel | 10 -8 torr @ 72° F | 3705N19 | 000000 |
| 3" | 4.33" | 80 | ISO-K | 3" | 5.71" | 80 | ISO-F | Viton® Fluoroelastomer Rubber | 304 Stainless Steel | 10 -8 torr @ 72° F | 3705N2 | 00000 |
| 4" | 5.12" | 100 | ISO-K | 4" | 6.5" | 100 | ISO-F | Viton® Fluoroelastomer Rubber | 304 Stainless Steel | 10 -8 torr @ 72° F | 3705N21 | 00000 |
| 6" | 7.09" | 160 | ISO-K | 6" | 8.86" | 160 | ISO-F | Viton® Fluoroelastomer Rubber | 304 Stainless Steel | 10 -8 torr @ 72° F | 3705N22 | 00000 |

























