Tri-clamp thermowells: 1½ and 2 in clamp, 2½ to 12 in insertion, ½ NPT top — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/tri-clamp-thermowells/  (CC BY 4.0)
Basis: Xem Studio design: the standard solid cap with a ⅜ in (9.53) well closed by a round tip, a Ø6.6 bore for a ¼ in (6.35) thermometer or probe stem, and a ½ NPT Class 3000 half coupling on top (tap-drill bore)
Catalog version: 2026-10-20

Sizes: see table below
- The temperature stick: clamp it into a port and slide a ¼ in stem thermometer or probe into the well, so the probe never touches the liquid. Insertion is measured from the clamp face to the tip.
- Pick the length so the tip sits in the middle of the liquid: in a 6 in × 18 in vessel through the top, 12 in; through a side port, 2½ to 4 in.
- Every clamp face is the ISO 2852 profile used across this site: 2.85 mm rim, flat face with the gasket groove (K 1.6 deep, R3 1.2 bottom, 23° walls, P2 0.8 edges) on C2, 20° back cone. Flange C3 / groove C2 / tube OD × wall, mm: ½–¾ in 25.0 / 20.4 (derived) / 12.7–19.05 × 1.65; 1–1½ in 50.5 / 43.5 / 25.4–38.1 × 1.65; 2 in 64.0 / 56.5 / 50.8 × 1.65; 2½ in 77.5 / 70.5 / 63.5 × 1.65; 3 in 91.0 / 83.5 / 76.2 × 1.65; 4 in 119.0 / 110.0 / 101.6 × 2.11; 6 in 166.9 (6.570 in) / 156.5 / 152.4 × 2.77; 8 in 217.7 (8.570 in) / 207.0 / 203.2 × 2.77; 10 in 268.5 / 261.0 / 254.0 × 3.40; 12 in 319.3 / 311.8 / 304.8 × 3.40.

clamp  insertion_in  insertion_mm  well_od_mm  bore_mm
1–1½  2.5  63.5  9.53  6.6
1–1½  4  101.6  9.53  6.6
1–1½  6  152.4  9.53  6.6
1–1½  9  228.6  9.53  6.6
1–1½  12  304.8  9.53  6.6
2  2.5  63.5  9.53  6.6
2  4  101.6  9.53  6.6
2  6  152.4  9.53  6.6
2  9  228.6  9.53  6.6
2  12  304.8  9.53  6.6

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- ASME: B1.20.1 Pipe threads, general purpose (NPT): major diameter, L2, tap drill; B16.11 forged fittings (Class 3000 couplings); B36.10 Sch 40 bore — standard — ASME; dimensions are facts [verify license at link] — https://www.asme.org/codes-standards/find-codes-standards/b1-20-1-pipe-threads-general-purpose-inch
- GW Kent: Tri-clamp fittings guide: tube OD, flange OD and ID per size to 12 in; solid cap thickness — web — publisher's guide; dimensions cited — https://www.gwkent.com/triclamp-guide
- Rubber Fab: Tri-Clamp gasket dimensional chart: gasket ID, OD and bead diameter per size (2 in bead 2.22 in / 56.50 mm, 1.5 in 1.71 / 43.50, 3 in 3.29 / 83.50) — PDF — maker chart; dimensions are facts [verify license at link] — https://shop.andersonprocess.com/media/assets/product/documents/rubber-fab-tri-clamp-dimensions.pdf

Free files (CC BY 4.0, Xem Studio; STEP + STL, 10 parts): https://xemstudio.com/files/hardware/tri-clamp-thermowells/index.json
API: https://xemstudio.com/api/geometry?object=tri-clamp-thermowells