Tri-clamp clamps (printable two-bolt), hot-joint gaskets and heat shields: every flange size, ½ to 4 in — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/tri-clamp-clamps/  (CC BY 4.0)
Basis: Groove derived from the ISO 2852 ferrule on this site: 2.85 mm rim, 20° back cone, C3 rim diameter, Type B gasket web 1.7 mm between the lands; two-bolt closure: groove contact after 0.4 mm of travel, 0.6 mm more before the halves meet (≈0.44 mm gasket squeeze)
Catalog version: 2026-10-20

Sizes: see table below
- The groove is the ferrule's own back cone mirrored: as the two M5 bolts pull the halves together, the 20° walls wedge the rims toward each other and squeeze the gasket. Each half has 1.0 mm to travel: the walls touch the rims after 0.4 mm and the last 0.6 mm squeezes the gasket about 0.44 mm (0.6 × tan 20° per rim) before the halves meet, so a closed gap means a seated joint.
- The groove follows the ISO 2852 rim, so the clamp's working temperature is set by what it is made of; at a flame-side joint the clamp has to take that joint's temperature.
- Hot joints: the stock silicone/EPDM gasket is good to roughly 150–200 °C.
- Bore over the tube: tube OD + 2 mm (no contact, designed); M5 holes Ø5.5 (ISO 273); nut traps 8 AF exact (see Mating features). Drop M5 nuts into the traps; M5 × 30 screws through both lugs. Tighten evenly until the gap between the halves is just closed on both sides.
- LES: the clamps and hot gaskets every tri-clamp engine on this shelf needs.

size  tube_od_mm  rim_c3_mm  clamp_od_mm  clamp_width_mm  groove_throat_mm  contact_after_mm  bolts
0.75  19.1  25.0  34.0  13.3  7.4  0.4  2 × M5 × 30 + nuts
1.5  38.1  50.5  59.5  15.7  7.4  0.4  2 × M5 × 30 + nuts
2  50.8  64.0  73.0  16.0  7.4  0.4  2 × M5 × 30 + nuts
2.5  63.5  77.5  86.5  16.3  7.4  0.4  2 × M5 × 30 + nuts
3  76.2  91.0  100.0  16.5  7.4  0.4  2 × M5 × 30 + nuts
4  101.6  119.0  128.0  17.5  7.4  0.4  2 × M5 × 30 + nuts

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, 18 parts): https://xemstudio.com/files/hardware/tri-clamp-clamps/index.json
API: https://xemstudio.com/api/geometry?object=tri-clamp-clamps