Right-triangle ruler 120 × 40 × 4 (half of a sliding parallel ruler) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/parallel-ruler-triangle-120x40/  (CC BY 4.0)
Basis: Xem Studio design following Brown's figure (1868); true size, no printing allowance
Catalog version: 2026-10-20

Overall (mm): length 120.0, width 40.0, height 4.0
- Right triangle with 120 and 40 mm legs, 4 mm thick: two of them, laid hypotenuse to hypotenuse, form a 120 × 40 rectangle whose long edges stay parallel as one triangle slides along the other.
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

dimension  value
legs  120 × 40 mm
hypotenuse  126.49 mm
thickness  4 mm

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Henry T. Brown (1868, public domain): Five Hundred and Seven Mechanical Movements — scan on archive.org — web — Publisher's page; dimensions are facts — https://archive.org/details/fivehundredseven00browiala
- 507movements.com: Brown's movement No. 322: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_322.html
- Xem Studio: drawing — web — Publisher's page; dimensions are facts — https://xemstudio.com/objects/sliding-triangle-parallel-ruler-mechanism/

Free files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/parallel-ruler-triangle-120x40/index.json
API: https://xemstudio.com/api/geometry?object=parallel-ruler-triangle-120x40