# Printable tri-clamp (45°): racking arm: 1½ in clamp body and ½ in arms, 2 to 6 in reach

> What is a tri-clamp racking arm (3D printable)?

- Category: Hardware › Printable tri-clamp
- Kind: Hardware
- Basis: Xem Studio design: a 1½ in clamp body with a sealed bore for ½ in tube (two O-rings), and a bent arm that turns inside the vessel; printable 45° back cone
- Page: https://xemstudio.com/objects/printable-tri-clamp-racking-arms/ · JSON: https://xemstudio.com/api/geometry?object=printable-tri-clamp-racking-arms · Plain text: https://xemstudio.com/objects/printable-tri-clamp-racking-arms/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.
- Turn the arm down to draw from the bottom, up to rack clear beer off the yeast. Fits a 1½ in side port on a fermenter.
- 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

| reach_in | reach_mm | tube_od_mm | o_rings |
|---|---|---|---|
| 2 | 50.8 | 12.7 | AS568-012 × 2 |
| 4 | 101.6 | 12.7 | AS568-012 × 2 |
| 6 | 152.4 | 12.7 | AS568-012 × 2 |

## Where the files are

- 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 (4 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/printable-tri-clamp-racking-arms/index.json

- racking-arm-body-1.5in-45: [STEP](https://xemstudio.com/files/hardware/printable-tri-clamp-racking-arms/racking-arm-body-1.5in-45.step) · [STL](https://xemstudio.com/files/hardware/printable-tri-clamp-racking-arms/racking-arm-body-1.5in-45.stl) — 1½ in clamp body: Ø24 boss 40 long, Ø12.8 bore with two AS568-012 O-ring grooves for ½ in tube — printable, 45° rims
- racking-arm-tube-2in-45: [STEP](https://xemstudio.com/files/hardware/printable-tri-clamp-racking-arms/racking-arm-tube-2in-45.step) · [STL](https://xemstudio.com/files/hardware/printable-tri-clamp-racking-arms/racking-arm-tube-2in-45.stl) — ½ in (Ø12.7 × 1.6) arm: 60 straight through the body, 90° bend on R25, 2 in reach — printable, 45° rims
- racking-arm-tube-4in-45: [STEP](https://xemstudio.com/files/hardware/printable-tri-clamp-racking-arms/racking-arm-tube-4in-45.step) · [STL](https://xemstudio.com/files/hardware/printable-tri-clamp-racking-arms/racking-arm-tube-4in-45.stl) — ½ in (Ø12.7 × 1.6) arm: 60 straight through the body, 90° bend on R25, 4 in reach — printable, 45° rims
- racking-arm-tube-6in-45: [STEP](https://xemstudio.com/files/hardware/printable-tri-clamp-racking-arms/racking-arm-tube-6in-45.step) · [STL](https://xemstudio.com/files/hardware/printable-tri-clamp-racking-arms/racking-arm-tube-6in-45.stl) — ½ in (Ø12.7 × 1.6) arm: 60 straight through the body, 90° bend on R25, 6 in reach — 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.

**What seals the arm?**

Two AS568-012 O-rings in the body bore; the arm turns in them.

## Fits with

- [Tri-clamp racking arm: 1½ in clamp body and ½ in arms, 2 to 6 in reach](https://xemstudio.com/objects/tri-clamp-racking-arms/)
- [Tri-clamp dip-tube caps: 1½ and 2 in, ⅜ in tube 6 to 24 in long](https://xemstudio.com/objects/tri-clamp-dip-tube-caps/)
- [Tri-clamp vessels with a dished or round welded bottom: 4, 6 and 8 in, 12 to 24 in deep](https://xemstudio.com/objects/tri-clamp-dished-bottom-vessels/)
- [Tri-clamp butterfly valves, printable: 1½ to 4 in](https://xemstudio.com/objects/tri-clamp-butterfly-valves/)
- [Printable tri-clamp (45°): two-bolt clamps, ½ to 8 in](https://xemstudio.com/objects/printable-tri-clamp-clamps/)