Tri-clamp flat gasket (hot joint, bore ID): 1.7 mm ring, ½ to 4 in — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/tri-clamp-hot-gasket/  (CC BY 4.0)
Basis: Flat ring: OD = C3 − 1 (flange less 0.5 per side), ID = tube bore, 1.7 mm thick (the ISO 2852 Type B web, the gap the clamp groove is drawn for)
Catalog version: 2026-10-20

Sizes: see table below
- A flat 1.7 mm ring that takes the place of the Type B gasket at a joint that runs too hot for an elastomer gasket, such as the flame end of a Stirling engine, or wherever a piston or displacer has to pass through the joint (its ID is the bore, so there is no lip in the way).
- OD is the flange diameter less 1 mm (Ø24.0 / 49.5 / 63.0 / 76.5 / 90.0 / 118.0); ID is the bore of the larger tube on that flange (Ø15.75 / 34.8 / 47.5 / 60.2 / 72.9 / 97.38).
- Thickness 1.7 mm is the Type B gasket's web, so the clamp's groove meets the rims after the same 0.4 mm of travel as at a Type B joint and the last 0.6 mm per half squeezes the ring (designed); a thinner ring would leave the clamp unable to reach the rims.

size_in  od_mm  id_mm  thickness_mm
½–¾  24.0  15.75  1.7
1–1½  49.5  34.8  1.7
2  63.0  47.5  1.7
2½  76.5  60.2  1.7
3  90.0  72.9  1.7
4  118.0  97.38  1.7

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- ISO: ISO 2852:1993 Stainless steel clamp pipe couplings for the food industry — standard — ISO [verify license at link] — https://www.iso.org/standard/7873.html
- Long Earth Society: Tri-clamp Stirling engine builds — web, video — LES site — https://longearthsociety.com/engineering/

Free files (CC BY 4.0, Xem Studio; STEP + STL, 6 parts): https://xemstudio.com/files/hardware/tri-clamp-hot-gasket/index.json
API: https://xemstudio.com/api/geometry?object=tri-clamp-hot-gasket