{
 "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-1-25",
 "name": "Spur gears, module 1.25: 10 to 80 teeth (20° involute)",
 "kind": "hardware",
 "category": "Hardware",
 "group": "Motion",
 "year": null,
 "question": "What is the pitch diameter of a module 1.25 spur gear?",
 "tags": [
  "gear",
  "spur gear",
  "module 1.25",
  "involute"
 ],
 "aliases": [
  "module 1.25 spur gear stl",
  "m1.25 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-1-25/",
 "sheet_txt": "https://xemstudio.com/objects/spur-gears-module-1-25/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 1.25 gears = m × (N1 + N2) / 2. Face width 10 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,
     12.5,
     15,
     9.38,
     10,
     3
    ],
    [
     12,
     15,
     17.5,
     11.88,
     10,
     4
    ],
    [
     14,
     17.5,
     20,
     14.38,
     10,
     5
    ],
    [
     15,
     18.75,
     21.25,
     15.62,
     10,
     5
    ],
    [
     16,
     20,
     22.5,
     16.88,
     10,
     6
    ],
    [
     18,
     22.5,
     25,
     19.38,
     10,
     7
    ],
    [
     20,
     25,
     27.5,
     21.88,
     10,
     8
    ],
    [
     22,
     27.5,
     30,
     24.38,
     10,
     9
    ],
    [
     24,
     30,
     32.5,
     26.88,
     10,
     9
    ],
    [
     25,
     31.25,
     33.75,
     28.12,
     10,
     10
    ],
    [
     28,
     35,
     37.5,
     31.88,
     10,
     11
    ],
    [
     30,
     37.5,
     40,
     34.38,
     10,
     12
    ],
    [
     32,
     40,
     42.5,
     36.88,
     10,
     13
    ],
    [
     35,
     43.75,
     46.25,
     40.62,
     10,
     14
    ],
    [
     36,
     45,
     47.5,
     41.88,
     10,
     15
    ],
    [
     40,
     50,
     52.5,
     46.88,
     10,
     16
    ],
    [
     42,
     52.5,
     55,
     49.38,
     10,
     17
    ],
    [
     45,
     56.25,
     58.75,
     53.12,
     10,
     19
    ],
    [
     48,
     60,
     62.5,
     56.88,
     10,
     20
    ],
    [
     50,
     62.5,
     65,
     59.38,
     10,
     21
    ],
    [
     56,
     70,
     72.5,
     66.88,
     10,
     23
    ],
    [
     60,
     75,
     77.5,
     71.88,
     10,
     25
    ],
    [
     64,
     80,
     82.5,
     76.88,
     10,
     25
    ],
    [
     70,
     87.5,
     90,
     84.38,
     10,
     25
    ],
    [
     72,
     90,
     92.5,
     86.88,
     10,
     25
    ],
    [
     80,
     100,
     102.5,
     96.88,
     10,
     25
    ]
   ]
  }
 },
 "sheet_text": "Spur gears, module 1.25: 10 to 80 teeth (20° involute) — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/spur-gears-module-1-25/  (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 1.25 gears = m × (N1 + N2) / 2. Face width 10 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  12.5  15.0  9.38  10.0  3\n12  15.0  17.5  11.88  10.0  4\n14  17.5  20.0  14.38  10.0  5\n15  18.75  21.25  15.62  10.0  5\n16  20.0  22.5  16.88  10.0  6\n18  22.5  25.0  19.38  10.0  7\n20  25.0  27.5  21.88  10.0  8\n22  27.5  30.0  24.38  10.0  9\n24  30.0  32.5  26.88  10.0  9\n25  31.25  33.75  28.12  10.0  10\n28  35.0  37.5  31.88  10.0  11\n30  37.5  40.0  34.38  10.0  12\n32  40.0  42.5  36.88  10.0  13\n35  43.75  46.25  40.62  10.0  14\n36  45.0  47.5  41.88  10.0  15\n40  50.0  52.5  46.88  10.0  16\n42  52.5  55.0  49.38  10.0  17\n45  56.25  58.75  53.12  10.0  19\n48  60.0  62.5  56.88  10.0  20\n50  62.5  65.0  59.38  10.0  21\n56  70.0  72.5  66.88  10.0  23\n60  75.0  77.5  71.88  10.0  25\n64  80.0  82.5  76.88  10.0  25\n70  87.5  90.0  84.38  10.0  25\n72  90.0  92.5  86.88  10.0  25\n80  100.0  102.5  96.88  10.0  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-1-25/index.json\nAPI: https://xemstudio.com/api/geometry?object=spur-gears-module-1-25\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-1-5",
  "spur-gears-module-2",
  "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 1.25, 20-tooth gear?",
   "a": "25 mm; tip 27.5 mm."
  },
  {
   "q": "Centre distance?",
   "a": "m × (N1 + N2) / 2: a 20 and a 40 tooth module 1.25 pair sit 37.5 mm apart."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "gear-m1-25-10t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-10t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-10t.stl",
   "note": "module 1.25, 10 teeth: pitch Ø12.5, tip Ø15, root Ø9.375, face 10, bore Ø3"
  },
  {
   "file": "gear-m1-25-12t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-12t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-12t.stl",
   "note": "module 1.25, 12 teeth: pitch Ø15, tip Ø17.5, root Ø11.875, face 10, bore Ø4"
  },
  {
   "file": "gear-m1-25-14t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-14t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-14t.stl",
   "note": "module 1.25, 14 teeth: pitch Ø17.5, tip Ø20, root Ø14.375, face 10, bore Ø5"
  },
  {
   "file": "gear-m1-25-15t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-15t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-15t.stl",
   "note": "module 1.25, 15 teeth: pitch Ø18.75, tip Ø21.25, root Ø15.625, face 10, bore Ø5"
  },
  {
   "file": "gear-m1-25-16t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-16t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-16t.stl",
   "note": "module 1.25, 16 teeth: pitch Ø20, tip Ø22.5, root Ø16.875, face 10, bore Ø6"
  },
  {
   "file": "gear-m1-25-18t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-18t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-18t.stl",
   "note": "module 1.25, 18 teeth: pitch Ø22.5, tip Ø25, root Ø19.375, face 10, bore Ø7"
  },
  {
   "file": "gear-m1-25-20t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-20t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-20t.stl",
   "note": "module 1.25, 20 teeth: pitch Ø25, tip Ø27.5, root Ø21.875, face 10, bore Ø8"
  },
  {
   "file": "gear-m1-25-22t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-22t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-22t.stl",
   "note": "module 1.25, 22 teeth: pitch Ø27.5, tip Ø30, root Ø24.375, face 10, bore Ø9"
  },
  {
   "file": "gear-m1-25-24t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-24t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-24t.stl",
   "note": "module 1.25, 24 teeth: pitch Ø30, tip Ø32.5, root Ø26.875, face 10, bore Ø9"
  },
  {
   "file": "gear-m1-25-25t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-25t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-25t.stl",
   "note": "module 1.25, 25 teeth: pitch Ø31.25, tip Ø33.75, root Ø28.125, face 10, bore Ø10"
  },
  {
   "file": "gear-m1-25-28t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-28t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-28t.stl",
   "note": "module 1.25, 28 teeth: pitch Ø35, tip Ø37.5, root Ø31.875, face 10, bore Ø11"
  },
  {
   "file": "gear-m1-25-30t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-30t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-30t.stl",
   "note": "module 1.25, 30 teeth: pitch Ø37.5, tip Ø40, root Ø34.375, face 10, bore Ø12"
  },
  {
   "file": "gear-m1-25-32t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-32t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-32t.stl",
   "note": "module 1.25, 32 teeth: pitch Ø40, tip Ø42.5, root Ø36.875, face 10, bore Ø13"
  },
  {
   "file": "gear-m1-25-35t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-35t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-35t.stl",
   "note": "module 1.25, 35 teeth: pitch Ø43.75, tip Ø46.25, root Ø40.625, face 10, bore Ø14"
  },
  {
   "file": "gear-m1-25-36t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-36t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-36t.stl",
   "note": "module 1.25, 36 teeth: pitch Ø45, tip Ø47.5, root Ø41.875, face 10, bore Ø15"
  },
  {
   "file": "gear-m1-25-40t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-40t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-40t.stl",
   "note": "module 1.25, 40 teeth: pitch Ø50, tip Ø52.5, root Ø46.875, face 10, bore Ø16"
  },
  {
   "file": "gear-m1-25-42t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-42t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-42t.stl",
   "note": "module 1.25, 42 teeth: pitch Ø52.5, tip Ø55, root Ø49.375, face 10, bore Ø17"
  },
  {
   "file": "gear-m1-25-45t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-45t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-45t.stl",
   "note": "module 1.25, 45 teeth: pitch Ø56.25, tip Ø58.75, root Ø53.125, face 10, bore Ø19"
  },
  {
   "file": "gear-m1-25-48t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-48t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-48t.stl",
   "note": "module 1.25, 48 teeth: pitch Ø60, tip Ø62.5, root Ø56.875, face 10, bore Ø20"
  },
  {
   "file": "gear-m1-25-50t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-50t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-50t.stl",
   "note": "module 1.25, 50 teeth: pitch Ø62.5, tip Ø65, root Ø59.375, face 10, bore Ø21"
  },
  {
   "file": "gear-m1-25-56t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-56t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-56t.stl",
   "note": "module 1.25, 56 teeth: pitch Ø70, tip Ø72.5, root Ø66.875, face 10, bore Ø23"
  },
  {
   "file": "gear-m1-25-60t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-60t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-60t.stl",
   "note": "module 1.25, 60 teeth: pitch Ø75, tip Ø77.5, root Ø71.875, face 10, bore Ø25"
  },
  {
   "file": "gear-m1-25-64t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-64t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-64t.stl",
   "note": "module 1.25, 64 teeth: pitch Ø80, tip Ø82.5, root Ø76.875, face 10, bore Ø25"
  },
  {
   "file": "gear-m1-25-70t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-70t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-70t.stl",
   "note": "module 1.25, 70 teeth: pitch Ø87.5, tip Ø90, root Ø84.375, face 10, bore Ø25"
  },
  {
   "file": "gear-m1-25-72t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-72t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-72t.stl",
   "note": "module 1.25, 72 teeth: pitch Ø90, tip Ø92.5, root Ø86.875, face 10, bore Ø25"
  },
  {
   "file": "gear-m1-25-80t",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-80t.step",
   "stl": "https://xemstudio.com/files/hardware/spur-gears-module-1-25/gear-m1-25-80t.stl",
   "note": "module 1.25, 80 teeth: pitch Ø100, tip Ø102.5, root Ø96.875, face 10, bore Ø25"
  }
 ],
 "markdown": "https://xemstudio.com/objects/spur-gears-module-1-25/index.md"
}