# L corner brackets for 20, 30, 40 and 10-series extrusion

> What size corner bracket for 2020 extrusion?

- Category: Hardware › Framing
- Kind: Hardware
- Basis: L bracket as wide and tall as the profile, one screw slot per leg at ISO 273 clearance (M5 Ø5.5, M6 Ø6.6, M8 Ø9.0, 1/4-20 Ø7.14), side gussets
- Page: https://xemstudio.com/objects/t-slot-corner-brackets/ · JSON: https://xemstudio.com/api/geometry?object=t-slot-corner-brackets · Plain text: https://xemstudio.com/objects/t-slot-corner-brackets/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 bracket is an L the size of the profile (20, 30, 40 or 25.4 mm cube) with a gusset on each side.
- Leg thickness is 3 mm on 20-series, 4.5 on 30, 6 on 40 and 3.81 on 10-series.
- Each leg has one screw slot at ISO 273 clearance: 20-series Ø5.5 × 6 long (M5), 30 Ø6.6 × 9 (M6), 40 Ø9 × 12 (M8), 10-series Ø7.14 × 7.62 (1/4-20).
- The legs are flat; there is no locating tongue on these brackets.

## 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 | size_mm | thickness_mm | slot_mm | screw |
|---|---|---|---|---|
| 20 | 20 | 3 | 5.5 × 6 | M5 |
| 30 | 30 | 4.5 | 6.6 × 9 | M6 |
| 40 | 40 | 6 | 9 × 12 | M8 |
| 10 (1 in) | 25.4 | 3.81 | 7.14 × 7.62 | 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-corner-brackets/index.json

- corner-bracket-20: [STEP](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/corner-bracket-20.step) · [STL](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/corner-bracket-20.stl) — 20-series L corner bracket 20 × 20, two slots 5.5 wide (M5 clearance) × 10 long end to end (4.5 travel), side gussets
- corner-bracket-30: [STEP](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/corner-bracket-30.step) · [STL](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/corner-bracket-30.stl) — 30-series L corner bracket 30 × 30, two slots 6.6 wide (M6 clearance) × 15 long end to end (8.4 travel), side gussets
- corner-bracket-40: [STEP](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/corner-bracket-40.step) · [STL](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/corner-bracket-40.stl) — 40-series L corner bracket 40 × 40, two slots 9 wide (M8 clearance) × 20 long end to end (11 travel), side gussets
- corner-bracket-10in: [STEP](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/corner-bracket-10in.step) · [STL](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/corner-bracket-10in.stl) — 10in-series L corner bracket 25.4 × 25.4, two slots 7.14 wide (1/4-20 clearance) × 12.7 long end to end (5.56 travel), side gussets

## 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/): legs flat on two profile faces at 90°

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

### Also needed
- [Slide-in T-nuts for 20, 30, 40 and 10-series (1 in) extrusion](https://xemstudio.com/objects/slide-in-t-nuts/): M5 / M6 / M8 / 1/4-20 screw through the slot into a T-nut

## Questions

**What screw for a 2020 corner bracket?**

M5 through the Ø5.5 slot into a 20-series T-nut.

**How thick is the 2020 bracket?**

3 mm legs, 20 × 20 × 20 overall with side gussets.

## Fits with

- [Slide-in T-nuts for 20, 30, 40 and 10-series (1 in) extrusion](https://xemstudio.com/objects/slide-in-t-nuts/)
- [Drop-in T-nuts for 20, 30, 40 and 10-series (1 in) extrusion](https://xemstudio.com/objects/drop-in-t-nuts/)
- [Inside corner gussets for 20, 30, 40 and 10-series extrusion](https://xemstudio.com/objects/t-slot-gussets/)
- [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/)