# End caps for 20, 30, 40 and 10-series extrusion (1, 2 and 4 cells)

> What size end cap for 2020 extrusion?

- Category: Hardware › Framing
- Kind: Hardware
- Basis: Cap = profile outline (exact), 3 thick; pins = profile centre bore (exact) × 8 long, one per cell
- Page: https://xemstudio.com/objects/t-slot-end-caps/ · JSON: https://xemstudio.com/api/geometry?object=t-slot-end-caps · Plain text: https://xemstudio.com/objects/t-slot-end-caps/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 cap is a 3 mm plate at the exact profile outline with R1.5 corners and one pin per cell, the profile's centre-bore diameter by 8 mm long with a 0.8 mm chamfer; 11 mm overall.
- Pins: Ø4.2 on 20-series, Ø6.8 on 30 and 40, Ø5.1 on 10-series.
- Sizes: 20-series 1 × 1 (20 × 20), 2 × 1 (40 × 20), 4 × 1 (80 × 20); 30-series 30 × 30; 40-series 40 × 40; 10-series 25.4 × 25.4.
- The pins press into the centre bores (press, see Mating features).

## 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 |
| end-cap pins | centre bore (4.2 / 6.8 / 5.1) | profile centre bore | press | end-cap-* |
| end-cap outline | profile outline | profile end face | designed | end-cap-* |

## Sizes

| file | outline_mm | pins | pin_dia_mm |
|---|---|---|---|
| end-cap-20-1x1 | 20 × 20 | 1 | 4.2 |
| end-cap-20-2x1 | 40 × 20 | 2 | 4.2 |
| end-cap-20-4x1 | 80 × 20 | 4 | 4.2 |
| end-cap-30-1x1 | 30 × 30 | 1 | 6.8 |
| end-cap-40-1x1 | 40 × 40 | 1 | 6.8 |
| end-cap-10in-1x1 | 25.4 × 25.4 | 1 | 5.1 |

## 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 (6 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/t-slot-end-caps/index.json

- end-cap-20-1x1: [STEP](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/end-cap-20-1x1.step) · [STL](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/end-cap-20-1x1.stl) — 20-series end cap, 1 × 1 cells, pins Ø4.2 (the centre bore, exact) press into the bores
- end-cap-20-2x1: [STEP](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/end-cap-20-2x1.step) · [STL](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/end-cap-20-2x1.stl) — 20-series end cap, 2 × 1 cells, pins Ø4.2 (the centre bore, exact) press into the bores
- end-cap-20-4x1: [STEP](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/end-cap-20-4x1.step) · [STL](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/end-cap-20-4x1.stl) — 20-series end cap, 4 × 1 cells, pins Ø4.2 (the centre bore, exact) press into the bores
- end-cap-30-1x1: [STEP](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/end-cap-30-1x1.step) · [STL](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/end-cap-30-1x1.stl) — 30-series end cap, 1 × 1 cells, pins Ø6.8 (the centre bore, exact) press into the bores
- end-cap-40-1x1: [STEP](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/end-cap-40-1x1.step) · [STL](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/end-cap-40-1x1.stl) — 40-series end cap, 1 × 1 cells, pins Ø6.8 (the centre bore, exact) press into the bores
- end-cap-10in-1x1: [STEP](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/end-cap-10in-1x1.step) · [STL](https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/end-cap-10in-1x1.stl) — 10in-series end cap, 1 × 1 cells, pins Ø5.1 (the centre bore, exact) press into the bores

## 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/): pins in the profile centre bores (press)

### Alternatives
- [Extrusion end feet for 20, 30, 40 and 10-series](https://xemstudio.com/objects/t-slot-feet/): a foot instead of a flat cap

## Questions

**What size pin for a 2020 end cap?**

Ø4.2, the profile's centre bore, 8 mm long.

**Is there a cap for 2040 and 2080?**

Yes: end-cap-20-2x1 (40 × 20) and end-cap-20-4x1 (80 × 20).

## Fits with

- [Extrusion end feet for 20, 30, 40 and 10-series](https://xemstudio.com/objects/t-slot-feet/)
- [Snap-in slot covers for 20, 30, 40 and 10-series extrusion (100 mm)](https://xemstudio.com/objects/t-slot-covers/)
- [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/)