# Push-fit fitting envelopes: 4 / 6 / 8 mm tube, G1/8 and G1/4 thread stubs

> What are the dimensions of a 6 mm push-fit fitting?

- Category: Hardware › Pipe & fittings
- Kind: Hardware
- Basis: Push-fit (push-to-connect) envelope: socket = PU tube OD, 12 deep; BSPP thread stub at the G major diameter (G1/8 Ø9.73, G1/4 Ø13.16)
- Page: https://xemstudio.com/objects/push-fit-fittings/ · JSON: https://xemstudio.com/api/geometry?object=push-fit-fittings · Plain text: https://xemstudio.com/objects/push-fit-fittings/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); linked files under their publishers' licenses

**Exact dimensions.** Every file is drawn at true size with no printing tolerance. The holes and pins that meet another part are listed below under Mating features, with the fit each joint needs; open those by your printer's or process's clearance before making the part.

## Notes

- Each file is an envelope of a straight push-fit fitting: a Ø(tube OD + 8) × 14 body, a 2 mm collar on top, and an 8 mm thread stub below; 24 mm overall.
- The tube socket is drawn at the PU tube OD exactly (Ø4, Ø6, Ø8) and 12 mm deep, with a through bore of Ø2, Ø4 or Ø6.
- Thread stubs are plain cylinders at the BSPP major diameter: G1/8 Ø9.73, G1/4 Ø13.16; threads are not modelled.
- Sizes: 4 mm tube / G1/8, 6 mm / G1/8, 6 mm / G1/4, 8 mm / G1/4.

## Mating features (exact size; open press / slide / run / socket by your process clearance, leave designed and clamp as drawn)

| feature | exact | mates with | fit | files |
|---|---|---|---|---|
| tube socket | Ø4 / Ø6 / Ø8 × 12 | PU tube OD | press | pushfit-* |
| thread stub | G1/8 Ø9.73 / G1/4 Ø13.16 | female BSPP port | designed | pushfit-* |

## Sizes

| file | tube_od_mm | socket_depth_mm | thread | stub_od_mm | overall_mm |
|---|---|---|---|---|---|
| pushfit-4mm-g1-8 | 4 | 12 | G1/8 | 9.73 | 24 |
| pushfit-6mm-g1-8 | 6 | 12 | G1/8 | 9.73 | 24 |
| pushfit-6mm-g1-4 | 6 | 12 | G1/4 | 13.16 | 24 |
| pushfit-8mm-g1-4 | 8 | 12 | G1/4 | 13.16 | 24 |

## Where the files are

- Wikipedia: [Hose barb](https://en.wikipedia.org/wiki/Hose_barb) — web — CC BY-SA 4.0 (text)
- Wikipedia: [Push-fit fitting](https://en.wikipedia.org/wiki/Push-to-connect_fitting) — web — CC BY-SA 4.0 (text)
- McMaster-Carr: [Tubing (free STEP per part, for your own design use; no redistribution)](https://www.mcmaster.com/products/tubing/) — STEP, PDF — McMaster-Carr site terms (verify at link)
- Long Earth Society: [Engine and rig builds](https://longearthsociety.com/engineering/) — web, video — LES site

## Free STEP/STL (4 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/push-fit-fittings/index.json

- pushfit-4mm-g1-8: [STEP](https://xemstudio.com/files/hardware/silicone-tube-and-fittings/pushfit-4mm-g1-8.step) · [STL](https://xemstudio.com/files/hardware/silicone-tube-and-fittings/pushfit-4mm-g1-8.stl) — push-fit fitting envelope: body Ø12 × 14, release collet Ø8 × 2, Ø4 tube socket 12 deep from the collet face, G1/8 thread stub (Ø9.73 major) × 8
- pushfit-6mm-g1-8: [STEP](https://xemstudio.com/files/hardware/silicone-tube-and-fittings/pushfit-6mm-g1-8.step) · [STL](https://xemstudio.com/files/hardware/silicone-tube-and-fittings/pushfit-6mm-g1-8.stl) — push-fit fitting envelope: body Ø14 × 14, release collet Ø10 × 2, Ø6 tube socket 12 deep from the collet face, G1/8 thread stub (Ø9.73 major) × 8
- pushfit-6mm-g1-4: [STEP](https://xemstudio.com/files/hardware/silicone-tube-and-fittings/pushfit-6mm-g1-4.step) · [STL](https://xemstudio.com/files/hardware/silicone-tube-and-fittings/pushfit-6mm-g1-4.stl) — push-fit fitting envelope: body Ø14 × 14, release collet Ø10 × 2, Ø6 tube socket 12 deep from the collet face, G1/4 thread stub (Ø13.16 major) × 8
- pushfit-8mm-g1-4: [STEP](https://xemstudio.com/files/hardware/silicone-tube-and-fittings/pushfit-8mm-g1-4.step) · [STL](https://xemstudio.com/files/hardware/silicone-tube-and-fittings/pushfit-8mm-g1-4.stl) — push-fit fitting envelope: body Ø16 × 14, release collet Ø12 × 2, Ø8 tube socket 12 deep from the collet face, G1/4 thread stub (Ø13.16 major) × 8

## How it fits

### Goes in or on
- [BSP (G) male thread envelopes 1/8 to 1 in (ISO 228-1)](https://xemstudio.com/objects/bsp-thread-envelopes/): G1/8 or G1/4 stub into a female BSPP port

### Connects to
- [PU pneumatic tube 4 to 12 mm OD (push-fit sizes)](https://xemstudio.com/objects/pu-pneumatic-tube/): tube OD into the socket drawn at the OD

### Alternatives
- [Hose barbs for 2, 3, 4, 6 and 8 mm ID tube](https://xemstudio.com/objects/hose-barbs/): for soft silicone tube

## Questions

**What thread is on a 6 mm push-fit fitting?**

Usually G1/8 or G1/4 BSPP; the stubs here are Ø9.73 and Ø13.16, the G major diameters.

**How deep does the tube go into a push-fit?**

The socket is drawn 12 mm deep at the tube OD.

## Fits with

- [PU pneumatic tube 4 to 12 mm OD (push-fit sizes)](https://xemstudio.com/objects/pu-pneumatic-tube/)
- [BSP (G) male thread envelopes 1/8 to 1 in (ISO 228-1)](https://xemstudio.com/objects/bsp-thread-envelopes/)
- [Hose barbs for 2, 3, 4, 6 and 8 mm ID tube](https://xemstudio.com/objects/hose-barbs/)
- [O-rings, common metric sizes (ISO 3601)](https://xemstudio.com/objects/o-rings-metric/)