T-slot attachments: slide-in and drop-in T-nuts, corner brackets, gussets, end caps, slot covers, feet, hole plates — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/t-slot-brackets-and-nuts/  (CC BY 4.0)
Basis: Sized to the profile entry: 20-series (6 mm slot, M5), 30-series (8 mm, M6/M8), 40-series (8 mm), 80/20 10-series (0.256 in, 1/4-20); T-nut envelopes match the common steel ones
Catalog version: 2026-10-20

Sizes: see table below
- Slide-in T-nut, 20-series: 10 × 10 × 4.5 mm body with a 5.6 mm tongue; drop-in: 10 × 5.6 × 4.5, rotates 90° in the slot. 30/40-series: 15.5 × 15.5 × 6.5 and 15.5 × 7.6 drop-in. Steel nuts are stronger; printed ones (PETG, M3/M4) hold light fixtures and are the pattern for the bracket pocket.
- Bracket rule: a flat face, a tongue 5.8 mm wide (6 mm slot) × 1.5 mm proud to stop rotation, and a slot (not a hole) along the extrusion so it slides to position. 20 mm L-bracket with two slots and side gussets carries a NEMA 17; the inside gusset makes a 90° frame joint square.
- End caps press pins into the centre bores (Ø4.2 + 0.15 on 20-series). Slot covers snap into the 6 mm opening and hide wiring. Feet take an M5 into the bore. Plates on the slot pitch give you a mounting grid.
- Everything is parametrized from the extrusion sheet; scale the 20-series parts by 1.5 for 30, by 2 for 40 only where the slot width allows (it doesn't: 30/40 share the 8 mm slot, so the tongue stays 7.8).

part  20-series  30-series  40-series  10-series (in)
slide-in T-nut  10 × 10 × 4.5, M3–M5  15.5 × 15.5 × 6.5, M5–M8  19 × 19 × 7, M6/M8  12.7 × 13.4 × 4.8, 1/4-20
drop-in T-nut  10 × 5.6 × 4.5  15.5 × 7.6 × 6.5  19 × 7.6 × 7  13.4 × 6.1 × 4.8
corner bracket  20 × 20 × 20, 3 thick  30 × 30 × 30, 4.5  40 × 40 × 40, 6  25.4 cube, 4
gusset  20 × 20  30 × 30  40 × 40  25.4
end cap pins  Ø4.35  Ø6.95  Ø6.95  Ø5.25
slot cover  6 mm  8 mm  8 mm  6.5 mm
screws  M5 button, M4/M3 with printed nuts  M6 / M8  M8  1/4-20 BHCS

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, 46 parts): https://xemstudio.com/files/hardware/t-slot-brackets-and-nuts/index.json
API: https://xemstudio.com/api/geometry?object=t-slot-brackets-and-nuts