2020 aluminum extrusion — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/2020-extrusion/  (CC BY 4.0)
Basis: industry standard profile; two slot families
Catalog version: 2026-10-20

Overall (mm): width 20, height 20
- 20 × 20 mm square; slot opening 6 mm (European/Misumi style, the common 3D-printer frame) or 5.26 mm (8020 10-series); center bore ~Ø4.2 for M5 tapping.
- Design brackets to the 6 mm slot with M5 T-nuts unless the frame is 8020-series.

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Wikipedia: T-slot structural framing — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/T-slot_structural_framing

Xem Studio scan: not needed; this is a published standard. The sheet is the geometry.
API: https://xemstudio.com/api/geometry?object=2020-extrusion