# 2 × 3 hole joining plates for 20, 30, 40 and 10-series extrusion

> What hole spacing for a 2020 joining plate?

- Category: Hardware › Framing
- Kind: Hardware
- Basis: Flat plate, 2 × 3 holes on the profile pitch, ISO 273 clearance holes, 5 mm thick
- Page: https://xemstudio.com/objects/t-slot-joining-plates/ · JSON: https://xemstudio.com/api/geometry?object=t-slot-joining-plates · Plain text: https://xemstudio.com/objects/t-slot-joining-plates/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 plate is 5 mm thick with R3 corners and six holes in a 2 × 3 grid on the profile pitch, one hole per profile centreline.
- 20-series: 40 × 60, Ø5.5 holes (M5) on 20 mm pitch. 30-series: 60 × 90, Ø6.6 (M6) on 30. 40-series: 80 × 120, Ø9 (M8) on 40. 10-series: 50.8 × 76.2, Ø7.14 (1/4-20) on 25.4.
- Use it to join profiles in a T or L, or as a mounting grid.

## 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 |
|---|---|---|---|---|
| bracket / gusset / plate screw holes | Ø5.5 / 6.6 / 9.0 / 7.14 | M5 / M6 / M8 / 1/4-20 clearance | designed | all |

## Sizes

| series | plate_mm | pitch_mm | hole_mm | screw |
|---|---|---|---|---|
| 20 | 40 × 60 × 5 | 20 | 5.5 | M5 |
| 30 | 60 × 90 × 5 | 30 | 6.6 | M6 |
| 40 | 80 × 120 × 5 | 40 | 9 | M8 |
| 10 (1 in) | 50.8 × 76.2 × 5 | 25.4 | 7.14 | 1/4-20 |

## Where the files are

- Wikipedia: [T-slot nut](https://en.wikipedia.org/wiki/T-slot_nut) — web — CC BY-SA 4.0 (text)
- OpenBuilds: [Tee nuts and brackets for V-slot](https://openbuildspartstore.com/) — web, STEP — OpenBuilds site (verify at link)
- Long Earth Society: [Engine and rig builds on extrusion frames](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/t-slot-joining-plates/index.json

- plate-20-2x3: [STEP](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/plate-20-2x3.step) · [STL](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/plate-20-2x3.stl) — 20-series 2 × 3 hole plate on 20 mm pitch, 5 thick, Ø5.5 holes (M5 clearance)
- plate-30-2x3: [STEP](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/plate-30-2x3.step) · [STL](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/plate-30-2x3.stl) — 30-series 2 × 3 hole plate on 30 mm pitch, 5 thick, Ø6.6 holes (M6 clearance)
- plate-40-2x3: [STEP](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/plate-40-2x3.step) · [STL](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/plate-40-2x3.stl) — 40-series 2 × 3 hole plate on 40 mm pitch, 5 thick, Ø9 holes (M8 clearance)
- plate-10in-2x3: [STEP](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/plate-10in-2x3.step) · [STL](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/plate-10in-2x3.stl) — 10in-series 2 × 3 hole plate on 25.4 mm pitch, 5 thick, Ø7.14 holes (1/4-20 clearance)

## How it fits

### Goes in or on
- [Aluminium T-slot extrusion: 2020, 2040, 2060, 2080, V-slot, 3030, 3060, 4040, 4080, 1010, 1515](https://xemstudio.com/objects/t-slot-extrusions/): holes on the profile pitch over the slot centrelines

### Alternatives
- [Inside corner gussets for 20, 30, 40 and 10-series extrusion](https://xemstudio.com/objects/t-slot-gussets/): corner joint

### Also needed
- [Slide-in T-nuts for 20, 30, 40 and 10-series (1 in) extrusion](https://xemstudio.com/objects/slide-in-t-nuts/): screw through each hole into a T-nut

## Questions

**What hole spacing on a 2020 plate?**

20 mm, the profile pitch, with Ø5.5 holes for M5.

**How thick are the plates?**

5 mm for every series.

## Fits with

- [Inside corner gussets for 20, 30, 40 and 10-series extrusion](https://xemstudio.com/objects/t-slot-gussets/)
- [Slide-in T-nuts for 20, 30, 40 and 10-series (1 in) extrusion](https://xemstudio.com/objects/slide-in-t-nuts/)
- [Aluminium T-slot extrusion: 2020, 2040, 2060, 2080, V-slot, 3030, 3060, 4040, 4080, 1010, 1515](https://xemstudio.com/objects/t-slot-extrusions/)
- [2020 aluminum extrusion](https://xemstudio.com/objects/2020-extrusion/)
- [Button head socket screws, M2–M8 (ISO 7380)](https://xemstudio.com/objects/button-head-screws-metric/)