{
 "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": "gt2-pulleys",
 "name": "GT2 timing pulleys, 16T–60T (2 mm pitch)",
 "kind": "hardware",
 "category": "Hardware",
 "group": "Motion",
 "year": null,
 "question": "What is the outer diameter of a GT2 20 tooth pulley?",
 "tags": [
  "pulley",
  "gt2",
  "belt",
  "motion"
 ],
 "aliases": [
  "gt2 pulley",
  "20 tooth pulley",
  "gt2 20t",
  "timing pulley",
  "gt2 idler"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 7,
 "url": "https://xemstudio.com/objects/gt2-pulleys/",
 "sheet_txt": "https://xemstudio.com/objects/gt2-pulleys/sheet.txt",
 "sheet": {
  "basis": "GT2 (2 mm pitch) geometry: pitch diameter = teeth × 2 / π, OD = PD − 0.508 mm; flange and hub sizes typical of printer-kit aluminium pulleys",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "Pitch diameter sets the motion: 20T = 12.73 mm PD, so one motor turn moves the belt 40 mm. OD is 0.508 mm less than PD.",
   "Common bores 5 mm (NEMA 17) and 8 mm (idler shafts). Belt widths 6 mm (standard) and 10 mm (heavier axes).",
   "Tooth profile in these files is an approximation for fit and clearance, not a belt-grade profile; buy the aluminium pulley for the drive."
  ],
  "table": {
   "columns": [
    "teeth",
    "pitch_dia_mm",
    "od_mm",
    "flange_dia_mm",
    "belt_mm",
    "bore_mm"
   ],
   "rows": [
    [
     16,
     10.19,
     9.68,
     12.7,
     6,
     5
    ],
    [
     20,
     12.73,
     12.22,
     15.2,
     6,
     5
    ],
    [
     20,
     12.73,
     12.22,
     15.2,
     6,
     8
    ],
    [
     36,
     22.92,
     22.41,
     25.4,
     6,
     5
    ],
    [
     40,
     25.46,
     24.96,
     28,
     6,
     5
    ],
    [
     60,
     38.2,
     37.69,
     40.7,
     6,
     8
    ],
    [
     20,
     12.73,
     12.22,
     15.2,
     10,
     5
    ]
   ]
  }
 },
 "sheet_text": "GT2 timing pulleys, 16T–60T (2 mm pitch) — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/gt2-pulleys/  (CC BY 4.0)\nBasis: GT2 (2 mm pitch) geometry: pitch diameter = teeth × 2 / π, OD = PD − 0.508 mm; flange and hub sizes typical of printer-kit aluminium pulleys\nCatalog version: 2026-10-20\n\nSizes: see table below\n- Pitch diameter sets the motion: 20T = 12.73 mm PD, so one motor turn moves the belt 40 mm. OD is 0.508 mm less than PD.\n- Common bores 5 mm (NEMA 17) and 8 mm (idler shafts). Belt widths 6 mm (standard) and 10 mm (heavier axes).\n- Tooth profile in these files is an approximation for fit and clearance, not a belt-grade profile; buy the aluminium pulley for the drive.\n\nteeth  pitch_dia_mm  od_mm  flange_dia_mm  belt_mm  bore_mm\n16  10.19  9.68  12.7  6  5\n20  12.73  12.22  15.2  6  5\n20  12.73  12.22  15.2  6  8\n36  22.92  22.41  25.4  6  5\n40  25.46  24.96  28.0  6  5\n60  38.2  37.69  40.7  6  8\n20  12.73  12.22  15.2  10  5\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Wikipedia: Timing belt (camshaft) — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Timing_belt_(camshaft)\n- Gates: PowerGrip GT2 belt and pulley design guide — PDF — Gates site terms [verify license at link] — https://www.gates.com/us/en/power-transmission/synchronous-belts/powergrip-gt2.html\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 7 parts): https://xemstudio.com/files/hardware/gt2-pulleys/index.json\nAPI: https://xemstudio.com/api/geometry?object=gt2-pulleys\n",
 "sources": [
  {
   "publisher": "Wikipedia",
   "title": "Timing belt (camshaft)",
   "url": "https://en.wikipedia.org/wiki/Timing_belt_(camshaft)",
   "formats": [
    "web"
   ],
   "license": "CC BY-SA 4.0 (text)",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Gates",
   "title": "PowerGrip GT2 belt and pulley design guide",
   "url": "https://www.gates.com/us/en/power-transmission/synchronous-belts/powergrip-gt2.html",
   "formats": [
    "PDF"
   ],
   "license": "Gates site terms",
   "license_verified": false,
   "hosted": false
  }
 ],
 "xem": {
  "status": "free-files",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "nema-17-stepper",
  "set-screws-metric",
  "ball-bearings-metric",
  "2020-extrusion",
  "lead-screw-t8"
 ],
 "faq": [
  {
   "q": "What is the diameter of a 20 tooth GT2 pulley?",
   "a": "Pitch diameter 12.73 mm, outer diameter 12.22 mm, flanges about 16 mm. One revolution moves the belt 40 mm."
  },
  {
   "q": "What is the diameter of a 16 tooth GT2 pulley?",
   "a": "Pitch diameter 10.19 mm, OD 9.68 mm; 32 mm of belt per revolution."
  },
  {
   "q": "How far does a GT2 belt move per step?",
   "a": "With a 20T pulley on a 200-step motor at 16× microstepping: 40 mm / 3200 = 0.0125 mm per microstep (80 steps/mm)."
  },
  {
   "q": "What size is a GT2 idler?",
   "a": "Toothed idlers are 16T or 20T on a 3 mm or 5 mm bore bearing; smooth idlers are Ø16–18 mm. A 623 bearing stack (3×10×4) is the common DIY idler."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "gt2-16t-5",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/gt2-pulleys/gt2-16t-5.step",
   "stl": "https://xemstudio.com/files/hardware/gt2-pulleys/gt2-16t-5.stl",
   "note": "GT2 16T, bore 5, 6 mm belt; approximate tooth profile, two M3 set screws"
  },
  {
   "file": "gt2-20t-5",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/gt2-pulleys/gt2-20t-5.step",
   "stl": "https://xemstudio.com/files/hardware/gt2-pulleys/gt2-20t-5.stl",
   "note": "GT2 20T, bore 5, 6 mm belt; approximate tooth profile, two M3 set screws"
  },
  {
   "file": "gt2-20t-8",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/gt2-pulleys/gt2-20t-8.step",
   "stl": "https://xemstudio.com/files/hardware/gt2-pulleys/gt2-20t-8.stl",
   "note": "GT2 20T, bore 8, 6 mm belt; approximate tooth profile, two M3 set screws"
  },
  {
   "file": "gt2-36t-5",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/gt2-pulleys/gt2-36t-5.step",
   "stl": "https://xemstudio.com/files/hardware/gt2-pulleys/gt2-36t-5.stl",
   "note": "GT2 36T, bore 5, 6 mm belt; approximate tooth profile, two M3 set screws"
  },
  {
   "file": "gt2-40t-5",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/gt2-pulleys/gt2-40t-5.step",
   "stl": "https://xemstudio.com/files/hardware/gt2-pulleys/gt2-40t-5.stl",
   "note": "GT2 40T, bore 5, 6 mm belt; approximate tooth profile, two M3 set screws"
  },
  {
   "file": "gt2-60t-8",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/gt2-pulleys/gt2-60t-8.step",
   "stl": "https://xemstudio.com/files/hardware/gt2-pulleys/gt2-60t-8.stl",
   "note": "GT2 60T, bore 8, 6 mm belt; approximate tooth profile, two M3 set screws"
  },
  {
   "file": "gt2-20t-5-w10",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/gt2-pulleys/gt2-20t-5-w10.step",
   "stl": "https://xemstudio.com/files/hardware/gt2-pulleys/gt2-20t-5-w10.stl",
   "note": "GT2 20T, bore 5, 10 mm belt; approximate tooth profile, two M3 set screws"
  }
 ],
 "markdown": "https://xemstudio.com/objects/gt2-pulleys/index.md"
}