Round band Ø5, endless, 325.66 mm centreline, on two pulleys 100 mm apart — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/round-band-5-c100-pulleys-40/  (sheet CC BY 4.0; files Xem Studio Design License, https://xemstudio.com/license/)
Basis: Xem Studio design following Brown's figure (1868); true size, no printing allowance
Catalog version: 2026-10-20

Overall (mm): length 145.0, width 45.0, height 5.0
- Ø5 endless round band at its working shape on two equal pulleys 100 mm apart: centreline = 2 × 100 + 2π × 20 = 325.66 mm.
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

dimension  value
section  Ø5
centreline length  325.66 mm
centre distance  100 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. 257: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_257.html
- Xem Studio: drawing — web — Publisher's page; dimensions are facts — https://xemstudio.com/objects/round-groove-pulleys-round-band-mechanism/

Free files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/round-band-5-c100-pulleys-40/index.json
API: https://xemstudio.com/api/geometry?object=round-band-5-c100-pulleys-40