# Printable tri-clamp (45°): caps with PG13.5 probe ports (12 mm pH, dissolved O₂ and CO₂ probes): 1½ to 4 in

> How do I mount a 12 mm pH probe on a tri-clamp (3D printable)?

- Category: Hardware › Printable tri-clamp
- Kind: Hardware
- Basis: Xem Studio design: Xem Studio design on the standard solid cap: PG13.5 (DIN 40430: Ø20.4 major, 1.41 pitch, Ø18.6 core) in a Ø30 boss, drawn as the core bore over 12 mm of thread, Ø12.5 through for the 12 mm probe shaft; printable 45° back cone
- Page: https://xemstudio.com/objects/printable-tri-clamp-pg13-5-probe-ports/ · JSON: https://xemstudio.com/api/geometry?object=printable-tri-clamp-pg13-5-probe-ports · Plain text: https://xemstudio.com/objects/printable-tri-clamp-pg13-5-probe-ports/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); linked files under their publishers' licenses
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

**Exact dimensions.** True size, with no printing tolerance added.

## Notes

- 3D-printable tri-clamp: this is Xem Studio's print-friendly version of the standard sanitary fitting, drawn so it prints on an ordinary FDM or resin printer with no supports. Download the STL to print it, or the STEP to edit it. The files are true size (no printing allowance): add your own clearance in the slicer or CAD if your printer needs it.
- Most process probes (pH, ORP, dissolved oxygen, dissolved CO₂, conductivity) are 12 mm shafts with a PG13.5 thread on the head: they screw straight into this port and seal on their own O-ring.
- Probe length sets how deep the tip reaches below the clamp face; pick the probe so its tip sits in the liquid at your lowest fill.
- Printable tri-clamp: the ISO 2852 face and gasket groove are exactly standard, only the back cone behind each rim is 45° instead of 20°, so no rim overhangs more than 45° from vertical in any print orientation. Join these with the 45° clamps (printable-tri-clamp-clamps) and standard Type B gaskets; a 45° clamp fits only 45° rims, so keep a run all 45°. A 45° cone turns clamp force into face force at 1 : 1 (a 20° cone at 2.7 : 1), so tighten the clamp bolts harder or use M6.
- Print orientation: straight parts face down; elbows, tees and crosses with one face down; horizontal bores bridge their top, so keep them small or add a light tree support inside.
- 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.

## Sizes

| clamp | ports | pg_major_mm | core_mm | probe_mm |
|---|---|---|---|---|
| 1–1½ | 1 | 20.4 | 18.6 | 12.0 |
| 2 | 1 | 20.4 | 18.6 | 12.0 |
| 3 | 2 | 20.4 | 18.6 | 12.0 |
| 3 | 3 | 20.4 | 18.6 | 12.0 |
| 4 | 3 | 20.4 | 18.6 | 12.0 |

## Where the files are

- DIN: [DIN 40430 Pg (Panzergewinde) threads: PG13.5 Ø20.4 major, 1.41 pitch (18 tpi), Ø18.6 core; the thread of 12 mm process probes (pH, dissolved O2 / CO2)](https://www.din.de/en) — standard — DIN; dimensions are facts (verify at link)
- GW Kent: [Tri-clamp fittings guide: tube OD, flange OD and ID per size to 12 in; solid cap thickness](https://www.gwkent.com/triclamp-guide) — web — publisher's guide; dimensions cited
- 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)](https://shop.andersonprocess.com/media/assets/product/documents/rubber-fab-tri-clamp-dimensions.pdf) — PDF — maker chart; dimensions are facts (verify at link)

## Free STEP/STL (5 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/printable-tri-clamp-pg13-5-probe-ports/index.json

- pg13-5-cap-1.5in-x1-45: [STEP](https://xemstudio.com/files/hardware/printable-tri-clamp-pg13-5-probe-ports/pg13-5-cap-1.5in-x1-45.step) · [STL](https://xemstudio.com/files/hardware/printable-tri-clamp-pg13-5-probe-ports/pg13-5-cap-1.5in-x1-45.stl) — 1–1½ in cap with 1 × PG13.5 probe port: boss Ø30 × 16, core bore Ø18.6 × 12 (thread), Ø12.5 through — printable, 45° rims
- pg13-5-cap-2in-x1-45: [STEP](https://xemstudio.com/files/hardware/printable-tri-clamp-pg13-5-probe-ports/pg13-5-cap-2in-x1-45.step) · [STL](https://xemstudio.com/files/hardware/printable-tri-clamp-pg13-5-probe-ports/pg13-5-cap-2in-x1-45.stl) — 2 in cap with 1 × PG13.5 probe port: boss Ø30 × 16, core bore Ø18.6 × 12 (thread), Ø12.5 through — printable, 45° rims
- pg13-5-cap-3in-x2-45: [STEP](https://xemstudio.com/files/hardware/printable-tri-clamp-pg13-5-probe-ports/pg13-5-cap-3in-x2-45.step) · [STL](https://xemstudio.com/files/hardware/printable-tri-clamp-pg13-5-probe-ports/pg13-5-cap-3in-x2-45.stl) — 3 in cap with 2 × PG13.5 probe port: boss Ø30 × 16, core bore Ø18.6 × 12 (thread), Ø12.5 through — printable, 45° rims
- pg13-5-cap-3in-x3-45: [STEP](https://xemstudio.com/files/hardware/printable-tri-clamp-pg13-5-probe-ports/pg13-5-cap-3in-x3-45.step) · [STL](https://xemstudio.com/files/hardware/printable-tri-clamp-pg13-5-probe-ports/pg13-5-cap-3in-x3-45.stl) — 3 in cap with 3 × PG13.5 probe port: boss Ø30 × 16, core bore Ø18.6 × 12 (thread), Ø12.5 through — printable, 45° rims
- pg13-5-cap-4in-x3-45: [STEP](https://xemstudio.com/files/hardware/printable-tri-clamp-pg13-5-probe-ports/pg13-5-cap-4in-x3-45.step) · [STL](https://xemstudio.com/files/hardware/printable-tri-clamp-pg13-5-probe-ports/pg13-5-cap-4in-x3-45.stl) — 4 in cap with 3 × PG13.5 probe port: boss Ø30 × 16, core bore Ø18.6 × 12 (thread), Ø12.5 through — printable, 45° rims

## Questions

**Can I 3D print this?**

Yes. It is the 3D-printable version: every overhang is 45° or steeper, so it prints without supports, and the sealing face is standard ISO 2852, so a normal gasket and clamp fit.

**Which probes fit?**

Any 12 mm probe with a PG13.5 head: most industrial pH, ORP, DO and dissolved-CO₂ probes.

## Fits with

- [Tri-clamp caps with PG13.5 probe ports (12 mm pH, dissolved O₂ and CO₂ probes): 1½ to 4 in](https://xemstudio.com/objects/tri-clamp-pg13-5-probe-ports/)
- [Tri-clamp brewing sensor lids: 4, 6 and 8 in caps with every port a fermenter needs](https://xemstudio.com/objects/tri-clamp-brewing-sensor-lids/)
- [Tri-clamp probe gland caps: Ø4, Ø6 and ¼ in probes, 1 to 3 per cap](https://xemstudio.com/objects/tri-clamp-probe-gland-caps/)
- [Tri-clamp thermowells: 1½ and 2 in clamp, 2½ to 12 in insertion, ½ NPT top](https://xemstudio.com/objects/tri-clamp-thermowells/)
- [Printable tri-clamp (45°): two-bolt clamps, ½ to 8 in](https://xemstudio.com/objects/printable-tri-clamp-clamps/)