# Dowel pins with internal thread, ISO 8733: Ø6–Ø50 extraction thread, thread depth, counterbore

> What extraction thread, thread depth and counterbore does an ISO 8733 dowel pin with internal thread have for Ø6 to Ø50?

- Category: Hardware › Fasteners
- Kind: Standard part
- Basis: Westfield Fasteners' ISO 8733 table (d1, c1, c2, d2, P, d3, t1, t2, t3), cross-checked against OPAC's ISO 8733 table
- Page: https://xemstudio.com/objects/dowel-pins-internal-thread-iso-8733/ · JSON: https://xemstudio.com/api/geometry?object=dowel-pins-internal-thread-iso-8733 · Plain text: https://xemstudio.com/objects/dowel-pins-internal-thread-iso-8733/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); files CC BY 4.0 or their publisher's license
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

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

## Notes

- Columns: pin diameter d1, thread d2, counterbore d3, thread depth t1, counterbore depth t3, drawn length l. Hardened pins to ISO 8735 use the same d2 per diameter.
- One representative length per diameter is drawn; other lengths change l only. End chamfers c1/c2 (≈ values) are not drawn.

## 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 |
|---|---|---|---|---|
| pin | d1 (m6): Ø6 to Ø50 | reamed hole H7 of the same Ø | press | all |
| extraction thread | d2 × t1: M4 × 6 (Ø6) to M24 × 36 (Ø50); Ø10 M6 × 10 | extraction screw or slide hammer | designed | all |

## Sizes

| d1 | thread | d3 | t1 | t3 | l drawn |
|---|---|---|---|---|---|
| 6 | M4 | 4.3 | 6 | 1 | 20 |
| 8 | M5 | 5.3 | 8 | 1.2 | 25 |
| 10 | M6 | 6.4 | 10 | 1.2 | 30 |
| 12 | M6 | 6.4 | 12 | 1.2 | 30 |
| 16 | M8 | 8.4 | 16 | 1.5 | 40 |
| 20 | M10 | 10.5 | 18 | 1.5 | 50 |
| 25 | M16 | 17 | 24 | 2 | 60 |
| 30 | M20 | 21 | 30 | 2 | 80 |
| 40 | M20 | 21 | 30 | 2.5 | 100 |
| 50 | M24 | 25 | 36 | 2.5 | 120 |

## Where the files are

- Westfield Fasteners: [ISO 8733 extractable dowel pin: d1, c1, c2, d2, P, d3, t1, t2, t3](https://www.westfieldfasteners.co.uk/Standards/Pin-ExtDowel.html) — web — Publisher's page; dimensions are facts
- OPAC: [ISO 8733 table](https://www.opac.net/en/producto-170-iso-8733) — web — Publisher's page; dimensions are facts
- ISO (iTeh preview): [ISO 8735:1997 Table 1, hardened pins with internal thread](https://cdn.standards.iteh.ai/samples/21794/5336932a636449df82213642fd4cdca8/ISO-8735-1997.pdf) — web — Publisher's page; dimensions are facts

## Free STEP/STL (10 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/dowel-pins-internal-thread-iso-8733/index.json

- iso8733-6x20: [STEP](https://xemstudio.com/files/hardware/dowel-pins-internal-thread-iso-8733/iso8733-6x20.step) · [STL](https://xemstudio.com/files/hardware/dowel-pins-internal-thread-iso-8733/iso8733-6x20.stl) — ISO 8733 6×20: M4 to depth 6, counterbore Ø4.3×1
- iso8733-8x25: [STEP](https://xemstudio.com/files/hardware/dowel-pins-internal-thread-iso-8733/iso8733-8x25.step) · [STL](https://xemstudio.com/files/hardware/dowel-pins-internal-thread-iso-8733/iso8733-8x25.stl) — ISO 8733 8×25: M5 to depth 8, counterbore Ø5.3×1.2
- iso8733-10x30: [STEP](https://xemstudio.com/files/hardware/dowel-pins-internal-thread-iso-8733/iso8733-10x30.step) · [STL](https://xemstudio.com/files/hardware/dowel-pins-internal-thread-iso-8733/iso8733-10x30.stl) — ISO 8733 10×30: M6 to depth 10, counterbore Ø6.4×1.2
- iso8733-12x30: [STEP](https://xemstudio.com/files/hardware/dowel-pins-internal-thread-iso-8733/iso8733-12x30.step) · [STL](https://xemstudio.com/files/hardware/dowel-pins-internal-thread-iso-8733/iso8733-12x30.stl) — ISO 8733 12×30: M6 to depth 12, counterbore Ø6.4×1.2
- iso8733-16x40: [STEP](https://xemstudio.com/files/hardware/dowel-pins-internal-thread-iso-8733/iso8733-16x40.step) · [STL](https://xemstudio.com/files/hardware/dowel-pins-internal-thread-iso-8733/iso8733-16x40.stl) — ISO 8733 16×40: M8 to depth 16, counterbore Ø8.4×1.5
- iso8733-20x50: [STEP](https://xemstudio.com/files/hardware/dowel-pins-internal-thread-iso-8733/iso8733-20x50.step) · [STL](https://xemstudio.com/files/hardware/dowel-pins-internal-thread-iso-8733/iso8733-20x50.stl) — ISO 8733 20×50: M10 to depth 18, counterbore Ø10.5×1.5
- iso8733-25x60: [STEP](https://xemstudio.com/files/hardware/dowel-pins-internal-thread-iso-8733/iso8733-25x60.step) · [STL](https://xemstudio.com/files/hardware/dowel-pins-internal-thread-iso-8733/iso8733-25x60.stl) — ISO 8733 25×60: M16 to depth 24, counterbore Ø17×2
- iso8733-30x80: [STEP](https://xemstudio.com/files/hardware/dowel-pins-internal-thread-iso-8733/iso8733-30x80.step) · [STL](https://xemstudio.com/files/hardware/dowel-pins-internal-thread-iso-8733/iso8733-30x80.stl) — ISO 8733 30×80: M20 to depth 30, counterbore Ø21×2
- iso8733-40x100: [STEP](https://xemstudio.com/files/hardware/dowel-pins-internal-thread-iso-8733/iso8733-40x100.step) · [STL](https://xemstudio.com/files/hardware/dowel-pins-internal-thread-iso-8733/iso8733-40x100.stl) — ISO 8733 40×100: M20 to depth 30, counterbore Ø21×2.5
- iso8733-50x120: [STEP](https://xemstudio.com/files/hardware/dowel-pins-internal-thread-iso-8733/iso8733-50x120.step) · [STL](https://xemstudio.com/files/hardware/dowel-pins-internal-thread-iso-8733/iso8733-50x120.stl) — ISO 8733 50×120: M24 to depth 36, counterbore Ø25×2.5

## Questions

**What thread is in a 10 mm pull dowel?**

ISO 8733 Ø10: M6, 10 mm deep, with a Ø6.4 × 1.2 mm counterbore.

**Which pins have the same extraction thread?**

Hardened ISO 8735 pins use the same thread per diameter (M4 for Ø6 up to M24 for Ø50).

## Fits with

- [Dowel pins ISO 2338 and ISO 8734 (parallel pins, m6 and h8), 0.6–50 mm: diameter limits, chamfer c, commercial lengths](https://xemstudio.com/objects/dowel-pins-iso-2338-8734/)
- [Dowel pins, 2–6 mm (ISO 2338 / DIN 6325)](https://xemstudio.com/objects/dowel-pins-metric/)
- [Spring pins: slotted (ISO 8752, ASME B18.8.2) and coiled (ISO 8750): diameter, wall, chamfer, hole size, shear + hole gauges](https://xemstudio.com/objects/spring-pins-iso-8752-8750-asme-b18-8-2/)