{
 "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": "gear-rack-m1-120-full-depth",
 "name": "Gear rack, module 1, 120 mm, full-depth 20° teeth",
 "kind": "modern",
 "category": "Hardware",
 "group": "Mechanism parts",
 "year": null,
 "question": "What are the tooth dimensions of a module 1 rack?",
 "tags": [
  "mechanism part",
  "507 mechanical movements"
 ],
 "aliases": [
  "gear rack",
  "module 1 rack",
  "rack gear",
  "linear gear",
  "cremallera módulo 1",
  "Zahnstange Modul 1"
 ],
 "overall_mm": {
  "length": 120,
  "width": 11,
  "height": 8
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 1,
 "url": "https://xemstudio.com/objects/gear-rack-m1-120-full-depth/",
 "sheet_txt": "https://xemstudio.com/objects/gear-rack-m1-120-full-depth/sheet.txt",
 "sheet": {
  "basis": "Xem Studio design following Brown's figure (1868); true size, no printing allowance",
  "overall_mm": {
   "length": 120,
   "width": 11,
   "height": 8
  },
  "notes": [
   "Module 1 basic rack (ISO 53): straight 20° flanks, pitch π = 3.1416 mm, addendum 1 mm above the pitch line, dedendum 1.25 mm below it, tooth thickness π/2 on the pitch line; 120 × 8 mm, body to 10 mm below the pitch line, three Ø3.4 (M3 clearance) holes across it.",
   "A module 1 pinion of N teeth sits with its axis N/2 mm above the pitch line and moves the rack πN mm per turn.",
   "Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features)."
  ],
  "table": {
   "columns": [
    "dimension",
    "value"
   ],
   "rows": [
    [
     "module",
     "1"
    ],
    [
     "pressure angle",
     "20°"
    ],
    [
     "pitch",
     "3.1416 mm"
    ],
    [
     "addendum / dedendum",
     "1 / 1.25 mm"
    ],
    [
     "length × width",
     "120 × 8 mm"
    ],
    [
     "pitch line to back",
     "10 mm"
    ],
    [
     "holes",
     "3 × Ø3.4 at x = −45, 0, 45"
    ]
   ]
  }
 },
 "sheet_text": "Gear rack, module 1, 120 mm, full-depth 20° teeth — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/gear-rack-m1-120-full-depth/  (CC BY 4.0)\nBasis: Xem Studio design following Brown's figure (1868); true size, no printing allowance\nCatalog version: 2026-10-20\n\nOverall (mm): length 120.0, width 11.0, height 8.0\n- Module 1 basic rack (ISO 53): straight 20° flanks, pitch π = 3.1416 mm, addendum 1 mm above the pitch line, dedendum 1.25 mm below it, tooth thickness π/2 on the pitch line; 120 × 8 mm, body to 10 mm below the pitch line, three Ø3.4 (M3 clearance) holes across it.\n- A module 1 pinion of N teeth sits with its axis N/2 mm above the pitch line and moves the rack πN mm per turn.\n- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).\n\ndimension  value\nmodule  1\npressure angle  20°\npitch  3.1416 mm\naddendum / dedendum  1 / 1.25 mm\nlength × width  120 × 8 mm\npitch line to back  10 mm\nholes  3 × Ø3.4 at x = −45, 0, 45\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Henry T. Brown (1868, public domain): Five Hundred and Seven Mechanical Movements — scan on archive.org — web — Publisher's page; dimensions are facts — https://archive.org/details/fivehundredseven00browiala\n- 507movements.com: Brown's movement No. 113: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_113.html\n- Xem Studio: drawing — web — Publisher's page; dimensions are facts — https://xemstudio.com/objects/rack-and-pinion-mechanism/\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/gear-rack-m1-120-full-depth/index.json\nAPI: https://xemstudio.com/api/geometry?object=gear-rack-m1-120-full-depth\n",
 "sources": [
  {
   "publisher": "Henry T. Brown (1868, public domain)",
   "title": "Five Hundred and Seven Mechanical Movements — scan on archive.org",
   "url": "https://archive.org/details/fivehundredseven00browiala",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "507movements.com",
   "title": "Brown's movement No. 113: figure, his text and an animation",
   "url": "https://507movements.com/mm_113.html",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Xem Studio",
   "title": "drawing",
   "url": "https://xemstudio.com/objects/rack-and-pinion-mechanism/",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  }
 ],
 "xem": {
  "status": "free-files",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "rack-and-pinion-mechanism",
  "opposed-racks-and-pinion-mechanism"
 ],
 "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": "What are the tooth dimensions of a module 1 rack?",
   "a": "Module 1 basic rack (ISO 53): straight 20° flanks, pitch π = 3.1416 mm, addendum 1 mm above the pitch line, dedendum 1.25 mm below it, tooth thickness π/2 on the pitch line; 120 × 8 mm, body to 10 mm below the pitch line, three Ø3.4 (M3 clearance) holes across it."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "gear-rack-m1-120",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/gear-rack-m1-120-full-depth/gear-rack-m1-120.step",
   "stl": "https://xemstudio.com/files/hardware/gear-rack-m1-120-full-depth/gear-rack-m1-120.stl",
   "note": "rack, pitch line y = 0, a tooth centred at x = 0, z 0..8"
  }
 ],
 "markdown": "https://xemstudio.com/objects/gear-rack-m1-120-full-depth/index.md"
}