# Wrist pin Ø3 × 16

> What size wrist pin goes in a small Stirling piston or crosshead?

- Category: Stirling engines › Drives & mechanisms
- Kind: Hardware
- Basis: Ø3 at the piston boss and crosshead holes (fit: press); 0.4 chamfer both ends
- Page: https://xemstudio.com/objects/wrist-pin-3x16/ · JSON: https://xemstudio.com/api/geometry?object=wrist-pin-3x16 · Plain text: https://xemstudio.com/objects/wrist-pin-3x16/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

- A Ø3 × 16 pin, 0.4 mm chamfer on both ends.
- It presses into the power piston's wrist-pin boss or through the crosshead's cheeks (fit: press); the con-rod end turns on it.

## 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 |
|---|---|---|---|---|
| wrist pin | Ø3 | piston boss / crosshead clevis | press | wrist-pin-* |

## Sizes

| parameter | value |
|---|---|
| diameter | 3 |
| length | 16 |
| chamfers | 0.4 both ends |

## Where the files are

- Wikipedia: [Crosshead](https://en.wikipedia.org/wiki/Crosshead) — web — CC BY-SA 4.0 (text)
- Wikipedia: [Piston](https://en.wikipedia.org/wiki/Piston) — web — CC BY-SA 4.0 (text)
- James R. Senft: [Miniature Stirling engine piston fits (LTD book)](https://www.stirlingengine.com/) — book — reference (verify at link)
- Long Earth Society: [Engine builds](https://longearthsociety.com/engineering/) — web, video — LES site

## Free STEP/STL (1 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/wrist-pin-3x16/index.json

- wrist-pin-3x16: [STEP](https://xemstudio.com/files/hardware/power-cylinder-piston-crosshead/wrist-pin-3x16.step) · [STL](https://xemstudio.com/files/hardware/power-cylinder-piston-crosshead/wrist-pin-3x16.stl) — Ø3 × 16 wrist pin (dowel) for the piston boss

## How it fits

### Goes in or on
- [Power piston Ø16, 20, 25, 30 with Ø3 wrist-pin boss](https://xemstudio.com/objects/power-piston/): in the wrist-pin boss
- [Crosshead Ø8 × 24 for a Ø3 piston rod](https://xemstudio.com/objects/crosshead-8mm/): through the clevis cheeks

### Alternatives
- [Dowel pins, 2–6 mm (ISO 2338 / DIN 6325)](https://xemstudio.com/objects/dowel-pins-metric/): Ø3 × 16 dowel

## Questions

**What wrist pin fits the power piston?**

Ø3 × 16, pressed in the Ø3 boss hole.

**Can a stock dowel be used?**

Any Ø3 × 16 pin is the same size; dowel-pins-metric lists Ø3 × 16.

## Fits with

- [Power piston Ø16, 20, 25, 30 with Ø3 wrist-pin boss](https://xemstudio.com/objects/power-piston/)
- [Crosshead Ø8 × 24 for a Ø3 piston rod](https://xemstudio.com/objects/crosshead-8mm/)
- [Dowel pins, 2–6 mm (ISO 2338 / DIN 6325)](https://xemstudio.com/objects/dowel-pins-metric/)