# Spur gears, module 1: 10 to 80 teeth (20° involute) > What is the pitch diameter of a module 1 spur gear? - Category: Hardware › Motion - Kind: Hardware - 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) - Page: https://xemstudio.com/objects/spur-gears-module-1/ · JSON: https://xemstudio.com/api/geometry?object=spur-gears-module-1 · Plain text: https://xemstudio.com/objects/spur-gears-module-1/sheet.txt - License: dimension sheet CC BY 4.0 (Xem Studio); linked files under their publishers' licenses - Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/) **Exact dimensions.** True size, with no printing tolerance added. ## Notes - Centre distance of two module 1 gears = m × (N1 + N2) / 2. Face width 8 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. ## Sizes | teeth | pitch_dia_mm | tip_dia_mm | root_dia_mm | face_mm | bore_mm | |---|---|---|---|---|---| | 10 | 10.0 | 12.0 | 7.5 | 8.0 | 3 | | 12 | 12.0 | 14.0 | 9.5 | 8.0 | 3 | | 14 | 14.0 | 16.0 | 11.5 | 8.0 | 4 | | 15 | 15.0 | 17.0 | 12.5 | 8.0 | 4 | | 16 | 16.0 | 18.0 | 13.5 | 8.0 | 5 | | 18 | 18.0 | 20.0 | 15.5 | 8.0 | 5 | | 20 | 20.0 | 22.0 | 17.5 | 8.0 | 6 | | 22 | 22.0 | 24.0 | 19.5 | 8.0 | 7 | | 24 | 24.0 | 26.0 | 21.5 | 8.0 | 8 | | 25 | 25.0 | 27.0 | 22.5 | 8.0 | 8 | | 28 | 28.0 | 30.0 | 25.5 | 8.0 | 9 | | 30 | 30.0 | 32.0 | 27.5 | 8.0 | 10 | | 32 | 32.0 | 34.0 | 29.5 | 8.0 | 10 | | 35 | 35.0 | 37.0 | 32.5 | 8.0 | 11 | | 36 | 36.0 | 38.0 | 33.5 | 8.0 | 12 | | 40 | 40.0 | 42.0 | 37.5 | 8.0 | 13 | | 42 | 42.0 | 44.0 | 39.5 | 8.0 | 14 | | 45 | 45.0 | 47.0 | 42.5 | 8.0 | 15 | | 48 | 48.0 | 50.0 | 45.5 | 8.0 | 16 | | 50 | 50.0 | 52.0 | 47.5 | 8.0 | 17 | | 56 | 56.0 | 58.0 | 53.5 | 8.0 | 19 | | 60 | 60.0 | 62.0 | 57.5 | 8.0 | 20 | | 64 | 64.0 | 66.0 | 61.5 | 8.0 | 22 | | 70 | 70.0 | 72.0 | 67.5 | 8.0 | 24 | | 72 | 72.0 | 74.0 | 69.5 | 8.0 | 24 | | 80 | 80.0 | 82.0 | 77.5 | 8.0 | 25 | ## Where the files are - ISO: [ISO 53 standard basic rack (20° pressure angle, addendum 1 m, dedendum 1.25 m) and ISO 54 modules](https://www.iso.org/standard/5768.html) — standard — ISO; dimensions are facts (verify at link) ## Free STEP/STL (26 parts, CC BY 4.0, Xem Studio) Index: https://xemstudio.com/files/hardware/spur-gears-module-1/index.json - gear-m1-10t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-10t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-10t.stl) — module 1, 10 teeth: pitch Ø10, tip Ø12, root Ø7.5, face 8, bore Ø3 - gear-m1-12t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-12t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-12t.stl) — module 1, 12 teeth: pitch Ø12, tip Ø14, root Ø9.5, face 8, bore Ø3 - gear-m1-14t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-14t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-14t.stl) — module 1, 14 teeth: pitch Ø14, tip Ø16, root Ø11.5, face 8, bore Ø4 - gear-m1-15t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-15t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-15t.stl) — module 1, 15 teeth: pitch Ø15, tip Ø17, root Ø12.5, face 8, bore Ø4 - gear-m1-16t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-16t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-16t.stl) — module 1, 16 teeth: pitch Ø16, tip Ø18, root Ø13.5, face 8, bore Ø5 - gear-m1-18t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-18t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-18t.stl) — module 1, 18 teeth: pitch Ø18, tip Ø20, root Ø15.5, face 8, bore Ø5 - gear-m1-20t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-20t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-20t.stl) — module 1, 20 teeth: pitch Ø20, tip Ø22, root Ø17.5, face 8, bore Ø6 - gear-m1-22t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-22t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-22t.stl) — module 1, 22 teeth: pitch Ø22, tip Ø24, root Ø19.5, face 8, bore Ø7 - gear-m1-24t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-24t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-24t.stl) — module 1, 24 teeth: pitch Ø24, tip Ø26, root Ø21.5, face 8, bore Ø8 - gear-m1-25t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-25t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-25t.stl) — module 1, 25 teeth: pitch Ø25, tip Ø27, root Ø22.5, face 8, bore Ø8 - gear-m1-28t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-28t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-28t.stl) — module 1, 28 teeth: pitch Ø28, tip Ø30, root Ø25.5, face 8, bore Ø9 - gear-m1-30t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-30t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-30t.stl) — module 1, 30 teeth: pitch Ø30, tip Ø32, root Ø27.5, face 8, bore Ø10 - gear-m1-32t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-32t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-32t.stl) — module 1, 32 teeth: pitch Ø32, tip Ø34, root Ø29.5, face 8, bore Ø10 - gear-m1-35t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-35t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-35t.stl) — module 1, 35 teeth: pitch Ø35, tip Ø37, root Ø32.5, face 8, bore Ø11 - gear-m1-36t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-36t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-36t.stl) — module 1, 36 teeth: pitch Ø36, tip Ø38, root Ø33.5, face 8, bore Ø12 - gear-m1-40t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-40t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-40t.stl) — module 1, 40 teeth: pitch Ø40, tip Ø42, root Ø37.5, face 8, bore Ø13 - gear-m1-42t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-42t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-42t.stl) — module 1, 42 teeth: pitch Ø42, tip Ø44, root Ø39.5, face 8, bore Ø14 - gear-m1-45t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-45t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-45t.stl) — module 1, 45 teeth: pitch Ø45, tip Ø47, root Ø42.5, face 8, bore Ø15 - gear-m1-48t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-48t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-48t.stl) — module 1, 48 teeth: pitch Ø48, tip Ø50, root Ø45.5, face 8, bore Ø16 - gear-m1-50t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-50t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-50t.stl) — module 1, 50 teeth: pitch Ø50, tip Ø52, root Ø47.5, face 8, bore Ø17 - gear-m1-56t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-56t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-56t.stl) — module 1, 56 teeth: pitch Ø56, tip Ø58, root Ø53.5, face 8, bore Ø19 - gear-m1-60t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-60t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-60t.stl) — module 1, 60 teeth: pitch Ø60, tip Ø62, root Ø57.5, face 8, bore Ø20 - gear-m1-64t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-64t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-64t.stl) — module 1, 64 teeth: pitch Ø64, tip Ø66, root Ø61.5, face 8, bore Ø22 - gear-m1-70t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-70t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-70t.stl) — module 1, 70 teeth: pitch Ø70, tip Ø72, root Ø67.5, face 8, bore Ø24 - gear-m1-72t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-72t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-72t.stl) — module 1, 72 teeth: pitch Ø72, tip Ø74, root Ø69.5, face 8, bore Ø24 - gear-m1-80t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-80t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-1/gear-m1-80t.stl) — module 1, 80 teeth: pitch Ø80, tip Ø82, root Ø77.5, face 8, bore Ø25 ## Questions **Pitch diameter of a module 1, 20-tooth gear?** 20 mm; tip 22 mm. **Centre distance?** m × (N1 + N2) / 2: a 20 and a 40 tooth module 1 pair sit 30 mm apart. ## Fits with - [Spur gears, module 0.5: 10 to 80 teeth (20° involute)](https://xemstudio.com/objects/spur-gears-module-0-5/) - [Spur gears, module 0.8: 10 to 80 teeth (20° involute)](https://xemstudio.com/objects/spur-gears-module-0-8/) - [Spur gears, module 1.25: 10 to 80 teeth (20° involute)](https://xemstudio.com/objects/spur-gears-module-1-25/) - [Spur gears, module 1.5: 10 to 80 teeth (20° involute)](https://xemstudio.com/objects/spur-gears-module-1-5/) - [Spur gears, module 2: 10 to 80 teeth (20° involute)](https://xemstudio.com/objects/spur-gears-module-2/) - [Spur gears, involute 20°: module 0.5, 1 and 2, 12–60 teeth](https://xemstudio.com/objects/spur-gears-involute/)