End caps for 20, 30, 40 and 10-series extrusion (1, 2 and 4 cells) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/t-slot-end-caps/  (CC BY 4.0)
Basis: Cap = profile outline (exact), 3 thick; pins = profile centre bore (exact) × 8 long, one per cell
Catalog version: 2026-10-20

Sizes: see table below
- 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).

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

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Wikipedia: T-slot nut — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/T-slot_nut
- OpenBuilds: Tee nuts and brackets for V-slot — web, STEP — OpenBuilds site [verify license at link] — https://openbuildspartstore.com/
- Long Earth Society: Engine and rig builds on extrusion frames — web, video — LES site — https://longearthsociety.com/engineering/

Free files (CC BY 4.0, Xem Studio; STEP + STL, 6 parts): https://xemstudio.com/files/hardware/t-slot-end-caps/index.json
API: https://xemstudio.com/api/geometry?object=t-slot-end-caps