{
 "version": "2026-10-20",
 "license": "Dimension sheets are written by Xem Studio from the cited sources and are free to use (CC BY 4.0, attribute 'Xem Studio'). Linked files belong to their publishers under the license shown; Xem Studio does not host them. 'license_verified: false' means the license shown is from memory or the publisher's page as last read and should be confirmed at the link before commercial use.",
 "slug": "spur-gears-module-3",
 "name": "Spur gears, module 3: 10 to 80 teeth (20° involute)",
 "kind": "hardware",
 "category": "Hardware",
 "group": "Motion",
 "year": null,
 "question": "What is the pitch diameter of a module 3 spur gear?",
 "tags": [
  "gear",
  "spur gear",
  "module 3",
  "involute"
 ],
 "aliases": [
  "module 3 spur gear stl",
  "m3 gear dimensions",
  "spur gear calculator pitch diameter",
  "involute gear step file",
  "3d printable gear"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 26,
 "url": "https://xemstudio.com/objects/spur-gears-module-3/",
 "sheet_txt": "https://xemstudio.com/objects/spur-gears-module-3/sheet.txt",
 "sheet": {
  "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)",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "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."
  ],
  "table": {
   "columns": [
    "teeth",
    "pitch_dia_mm",
    "tip_dia_mm",
    "root_dia_mm",
    "face_mm",
    "bore_mm"
   ],
   "rows": [
    [
     10,
     30,
     36,
     22.5,
     24,
     8
    ],
    [
     12,
     36,
     42,
     28.5,
     24,
     10
    ],
    [
     14,
     42,
     48,
     34.5,
     24,
     12
    ],
    [
     15,
     45,
     51,
     37.5,
     24,
     13
    ],
    [
     16,
     48,
     54,
     40.5,
     24,
     14
    ],
    [
     18,
     54,
     60,
     46.5,
     24,
     16
    ],
    [
     20,
     60,
     66,
     52.5,
     24,
     18
    ],
    [
     22,
     66,
     72,
     58.5,
     24,
     20
    ],
    [
     24,
     72,
     78,
     64.5,
     24,
     23
    ],
    [
     25,
     75,
     81,
     67.5,
     24,
     24
    ],
    [
     28,
     84,
     90,
     76.5,
     24,
     25
    ],
    [
     30,
     90,
     96,
     82.5,
     24,
     25
    ],
    [
     32,
     96,
     102,
     88.5,
     24,
     25
    ],
    [
     35,
     105,
     111,
     97.5,
     24,
     25
    ],
    [
     36,
     108,
     114,
     100.5,
     24,
     25
    ],
    [
     40,
     120,
     126,
     112.5,
     24,
     25
    ],
    [
     42,
     126,
     132,
     118.5,
     24,
     25
    ],
    [
     45,
     135,
     141,
     127.5,
     24,
     25
    ],
    [
     48,
     144,
     150,
     136.5,
     24,
     25
    ],
    [
     50,
     150,
     156,
     142.5,
     24,
     25
    ],
    [
     56,
     168,
     174,
     160.5,
     24,
     25
    ],
    [
     60,
     180,
     186,
     172.5,
     24,
     25
    ],
    [
     64,
     192,
     198,
     184.5,
     24,
     25
    ],
    [
     70,
     210,
     216,
     202.5,
     24,
     25
    ],
    [
     72,
     216,
     222,
     208.5,
     24,
     25
    ],
    [
     80,
     240,
     246,
     232.5,
     24,
     25
    ]
   ]
  }
 },
 "sheet_text": "Spur gears, module 3: 10 to 80 teeth (20° involute) — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/spur-gears-module-3/  (CC BY 4.0)\nBasis: 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)\nCatalog version: 2026-10-20\n\nSizes: see table below\n- 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.\n\nteeth  pitch_dia_mm  tip_dia_mm  root_dia_mm  face_mm  bore_mm\n10  30.0  36.0  22.5  24.0  8\n12  36.0  42.0  28.5  24.0  10\n14  42.0  48.0  34.5  24.0  12\n15  45.0  51.0  37.5  24.0  13\n16  48.0  54.0  40.5  24.0  14\n18  54.0  60.0  46.5  24.0  16\n20  60.0  66.0  52.5  24.0  18\n22  66.0  72.0  58.5  24.0  20\n24  72.0  78.0  64.5  24.0  23\n25  75.0  81.0  67.5  24.0  24\n28  84.0  90.0  76.5  24.0  25\n30  90.0  96.0  82.5  24.0  25\n32  96.0  102.0  88.5  24.0  25\n35  105.0  111.0  97.5  24.0  25\n36  108.0  114.0  100.5  24.0  25\n40  120.0  126.0  112.5  24.0  25\n42  126.0  132.0  118.5  24.0  25\n45  135.0  141.0  127.5  24.0  25\n48  144.0  150.0  136.5  24.0  25\n50  150.0  156.0  142.5  24.0  25\n56  168.0  174.0  160.5  24.0  25\n60  180.0  186.0  172.5  24.0  25\n64  192.0  198.0  184.5  24.0  25\n70  210.0  216.0  202.5  24.0  25\n72  216.0  222.0  208.5  24.0  25\n80  240.0  246.0  232.5  24.0  25\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- 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\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 26 parts): https://xemstudio.com/files/hardware/spur-gears-module-3/index.json\nAPI: https://xemstudio.com/api/geometry?object=spur-gears-module-3\n",
 "sources": [
  {
   "publisher": "ISO",
   "title": "ISO 53 standard basic rack (20° pressure angle, addendum 1 m, dedendum 1.25 m) and ISO 54 modules",
   "url": "https://www.iso.org/standard/5768.html",
   "formats": [
    "standard"
   ],
   "license": "ISO; dimensions are facts",
   "license_verified": false,
   "hosted": false
  }
 ],
 "xem": {
  "status": "free-files",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "spur-gears-module-0-5",
  "spur-gears-module-0-8",
  "spur-gears-module-1",
  "spur-gears-module-1-25",
  "spur-gears-module-1-5",
  "spur-gears-involute"
 ],
 "fits": [],
 "dimensions": "exact (nominal, no printing tolerance)",
 "dimension_rule": "All geometry on Xem Studio is exact (nominal, true size) with no printing tolerance. Where a part meets another part, the object lists its mating features (feature, exact size, what it mates with, fit class: press, slide, run, socket, clamp or designed). Apply your process's allowance to those features only; 'designed' gaps are part of the design and stay as drawn.",
 "mating": [],
 "faq": [
  {
   "q": "Pitch diameter of a module 3, 20-tooth gear?",
   "a": "60 mm; tip 66 mm."
  },
  {
   "q": "Centre distance?",
   "a": "m × (N1 + N2) / 2: a 20 and a 40 tooth module 3 pair sit 90 mm apart."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "gear-m3-10t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-10t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-10t.stl",
   "note": "module 3, 10 teeth: pitch Ø30, tip Ø36, root Ø22.5, face 24, bore Ø8"
  },
  {
   "file": "gear-m3-12t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-12t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-12t.stl",
   "note": "module 3, 12 teeth: pitch Ø36, tip Ø42, root Ø28.5, face 24, bore Ø10"
  },
  {
   "file": "gear-m3-14t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-14t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-14t.stl",
   "note": "module 3, 14 teeth: pitch Ø42, tip Ø48, root Ø34.5, face 24, bore Ø12"
  },
  {
   "file": "gear-m3-15t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-15t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-15t.stl",
   "note": "module 3, 15 teeth: pitch Ø45, tip Ø51, root Ø37.5, face 24, bore Ø13"
  },
  {
   "file": "gear-m3-16t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-16t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-16t.stl",
   "note": "module 3, 16 teeth: pitch Ø48, tip Ø54, root Ø40.5, face 24, bore Ø14"
  },
  {
   "file": "gear-m3-18t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-18t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-18t.stl",
   "note": "module 3, 18 teeth: pitch Ø54, tip Ø60, root Ø46.5, face 24, bore Ø16"
  },
  {
   "file": "gear-m3-20t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-20t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-20t.stl",
   "note": "module 3, 20 teeth: pitch Ø60, tip Ø66, root Ø52.5, face 24, bore Ø18"
  },
  {
   "file": "gear-m3-22t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-22t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-22t.stl",
   "note": "module 3, 22 teeth: pitch Ø66, tip Ø72, root Ø58.5, face 24, bore Ø20"
  },
  {
   "file": "gear-m3-24t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-24t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-24t.stl",
   "note": "module 3, 24 teeth: pitch Ø72, tip Ø78, root Ø64.5, face 24, bore Ø23"
  },
  {
   "file": "gear-m3-25t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-25t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-25t.stl",
   "note": "module 3, 25 teeth: pitch Ø75, tip Ø81, root Ø67.5, face 24, bore Ø24"
  },
  {
   "file": "gear-m3-28t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-28t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-28t.stl",
   "note": "module 3, 28 teeth: pitch Ø84, tip Ø90, root Ø76.5, face 24, bore Ø25"
  },
  {
   "file": "gear-m3-30t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-30t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-30t.stl",
   "note": "module 3, 30 teeth: pitch Ø90, tip Ø96, root Ø82.5, face 24, bore Ø25"
  },
  {
   "file": "gear-m3-32t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-32t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-32t.stl",
   "note": "module 3, 32 teeth: pitch Ø96, tip Ø102, root Ø88.5, face 24, bore Ø25"
  },
  {
   "file": "gear-m3-35t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-35t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-35t.stl",
   "note": "module 3, 35 teeth: pitch Ø105, tip Ø111, root Ø97.5, face 24, bore Ø25"
  },
  {
   "file": "gear-m3-36t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-36t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-36t.stl",
   "note": "module 3, 36 teeth: pitch Ø108, tip Ø114, root Ø100.5, face 24, bore Ø25"
  },
  {
   "file": "gear-m3-40t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-40t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-40t.stl",
   "note": "module 3, 40 teeth: pitch Ø120, tip Ø126, root Ø112.5, face 24, bore Ø25"
  },
  {
   "file": "gear-m3-42t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-42t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-42t.stl",
   "note": "module 3, 42 teeth: pitch Ø126, tip Ø132, root Ø118.5, face 24, bore Ø25"
  },
  {
   "file": "gear-m3-45t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-45t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-45t.stl",
   "note": "module 3, 45 teeth: pitch Ø135, tip Ø141, root Ø127.5, face 24, bore Ø25"
  },
  {
   "file": "gear-m3-48t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-48t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-48t.stl",
   "note": "module 3, 48 teeth: pitch Ø144, tip Ø150, root Ø136.5, face 24, bore Ø25"
  },
  {
   "file": "gear-m3-50t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-50t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-50t.stl",
   "note": "module 3, 50 teeth: pitch Ø150, tip Ø156, root Ø142.5, face 24, bore Ø25"
  },
  {
   "file": "gear-m3-56t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-56t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-56t.stl",
   "note": "module 3, 56 teeth: pitch Ø168, tip Ø174, root Ø160.5, face 24, bore Ø25"
  },
  {
   "file": "gear-m3-60t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-60t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-60t.stl",
   "note": "module 3, 60 teeth: pitch Ø180, tip Ø186, root Ø172.5, face 24, bore Ø25"
  },
  {
   "file": "gear-m3-64t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-64t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-64t.stl",
   "note": "module 3, 64 teeth: pitch Ø192, tip Ø198, root Ø184.5, face 24, bore Ø25"
  },
  {
   "file": "gear-m3-70t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-70t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-70t.stl",
   "note": "module 3, 70 teeth: pitch Ø210, tip Ø216, root Ø202.5, face 24, bore Ø25"
  },
  {
   "file": "gear-m3-72t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-72t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-72t.stl",
   "note": "module 3, 72 teeth: pitch Ø216, tip Ø222, root Ø208.5, face 24, bore Ø25"
  },
  {
   "file": "gear-m3-80t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-80t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-3/gear-m3-80t.stl",
   "note": "module 3, 80 teeth: pitch Ø240, tip Ø246, root Ø232.5, face 24, bore Ø25"
  }
 ],
 "markdown": "https://xemstudio.com/objects/spur-gears-module-3/index.md"
}