Spur gears, module 3: 10 to 80 teeth (20° involute) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/spur-gears-module-3/  (CC BY 4.0)
Basis: ISO 53 basic rack: 20° pressure angle, addendum m, dedendum 1.25 m; pitch Ø = m × teeth, tip Ø = m × (teeth + 2), root Ø = m × (teeth − 2.5)
Catalog version: 2026-10-20

Sizes: see table below
- Centre distance of two module 3 gears = m × (N1 + N2) / 2. Face width 24 mm, plain bore (add a hub, key or set screw to suit). Teeth below 17 are drawn without profile shift, so they undercut as real unshifted gears do.

teeth  pitch_dia_mm  tip_dia_mm  root_dia_mm  face_mm  bore_mm
10  30.0  36.0  22.5  24.0  8
12  36.0  42.0  28.5  24.0  10
14  42.0  48.0  34.5  24.0  12
15  45.0  51.0  37.5  24.0  13
16  48.0  54.0  40.5  24.0  14
18  54.0  60.0  46.5  24.0  16
20  60.0  66.0  52.5  24.0  18
22  66.0  72.0  58.5  24.0  20
24  72.0  78.0  64.5  24.0  23
25  75.0  81.0  67.5  24.0  24
28  84.0  90.0  76.5  24.0  25
30  90.0  96.0  82.5  24.0  25
32  96.0  102.0  88.5  24.0  25
35  105.0  111.0  97.5  24.0  25
36  108.0  114.0  100.5  24.0  25
40  120.0  126.0  112.5  24.0  25
42  126.0  132.0  118.5  24.0  25
45  135.0  141.0  127.5  24.0  25
48  144.0  150.0  136.5  24.0  25
50  150.0  156.0  142.5  24.0  25
56  168.0  174.0  160.5  24.0  25
60  180.0  186.0  172.5  24.0  25
64  192.0  198.0  184.5  24.0  25
70  210.0  216.0  202.5  24.0  25
72  216.0  222.0  208.5  24.0  25
80  240.0  246.0  232.5  24.0  25

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- ISO: ISO 53 standard basic rack (20° pressure angle, addendum 1 m, dedendum 1.25 m) and ISO 54 modules — standard — ISO; dimensions are facts [verify license at link] — https://www.iso.org/standard/5768.html

Free files (CC BY 4.0, Xem Studio; STEP + STL, 26 parts): https://xemstudio.com/files/hardware/spur-gears-module-3/index.json
API: https://xemstudio.com/api/geometry?object=spur-gears-module-3