{
 "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": "cd-dvd-discs",
 "name": "CD / DVD disc Ø120 × 1.2 mm with Ø15 hole (and mini CD Ø80)",
 "kind": "standard",
 "category": "Hardware",
 "group": "Found & household materials",
 "year": null,
 "question": "What are the dimensions of a CD and its centre hole?",
 "tags": [
  "cd",
  "dvd",
  "disc",
  "flywheel",
  "found materials",
  "stirling",
  "long earth society"
 ],
 "aliases": [
  "cd dimensions",
  "cd center hole size",
  "dvd diameter mm",
  "mini cd size",
  "cd flywheel"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": true,
 "free_files": 2,
 "url": "https://xemstudio.com/objects/cd-dvd-discs/",
 "sheet_txt": "https://xemstudio.com/objects/cd-dvd-discs/sheet.txt",
 "sheet": {
  "basis": "ECMA-130 / ISO 9660 physical disc: Ø120 × 1.2 mm, Ø15 mm centre hole; mini CD Ø80",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "CD, DVD and Blu-ray discs share one physical size: Ø120.0 × 1.2 mm with a Ø15.0 mm centre hole (held to +0.1), about 16 g.",
   "The mini CD is Ø80 × 1.2 with the same Ø15 hole, about 7 g.",
   "Both files are flat rings drawn at those nominal sizes; the hubs in the can-engine kit are drawn with a Ø15.0 spigot for the hole (see Mating features there).",
   "On the can engine I use a CD as the flywheel: 16 g spread out to Ø120."
  ],
  "table": {
   "columns": [
    "disc",
    "dia_mm",
    "thickness_mm",
    "hole_mm",
    "mass_g"
   ],
   "rows": [
    [
     "CD / DVD / Blu-ray",
     120,
     1.2,
     15,
     16
    ],
    [
     "mini CD",
     80,
     1.2,
     15,
     7
    ]
   ]
  }
 },
 "sheet_text": "CD / DVD disc Ø120 × 1.2 mm with Ø15 hole (and mini CD Ø80) — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/cd-dvd-discs/  (CC BY 4.0)\nBasis: ECMA-130 / ISO 9660 physical disc: Ø120 × 1.2 mm, Ø15 mm centre hole; mini CD Ø80\nCatalog version: 2026-10-20\n\nSizes: see table below\n- CD, DVD and Blu-ray discs share one physical size: Ø120.0 × 1.2 mm with a Ø15.0 mm centre hole (held to +0.1), about 16 g.\n- The mini CD is Ø80 × 1.2 with the same Ø15 hole, about 7 g.\n- Both files are flat rings drawn at those nominal sizes; the hubs in the can-engine kit are drawn with a Ø15.0 spigot for the hole (see Mating features there).\n- On the can engine I use a CD as the flywheel: 16 g spread out to Ø120.\n\ndisc  dia_mm  thickness_mm  hole_mm  mass_g\nCD / DVD / Blu-ray  120  1.2  15  16\nmini CD  80  1.2  15  7\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Wikipedia: Compact disc — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Compact_disc\n- Wikipedia: Hard disk drive platter — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Hard_disk_drive_platter\n- Long Earth Society: Engine builds (videos and write-ups) — web, video — LES site — https://longearthsociety.com/engineering/\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 2 parts): https://xemstudio.com/files/hardware/cd-dvd-discs/index.json\nAPI: https://xemstudio.com/api/geometry?object=cd-dvd-discs\n",
 "sources": [
  {
   "publisher": "Wikipedia",
   "title": "Compact disc",
   "url": "https://en.wikipedia.org/wiki/Compact_disc",
   "formats": [
    "web"
   ],
   "license": "CC BY-SA 4.0 (text)",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Wikipedia",
   "title": "Hard disk drive platter",
   "url": "https://en.wikipedia.org/wiki/Hard_disk_drive_platter",
   "formats": [
    "web"
   ],
   "license": "CC BY-SA 4.0 (text)",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Long Earth Society",
   "title": "Engine builds (videos and write-ups)",
   "url": "https://longearthsociety.com/engineering/",
   "formats": [
    "web",
    "video"
   ],
   "license": "LES site",
   "license_verified": true,
   "hosted": false
  }
 ],
 "xem": {
  "status": "free-files",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "hdd-platters",
  "can-engine-cap",
  "crank-discs-5mm-bore",
  "bamboo-skewers",
  "beverage-cans"
 ],
 "fits": [
  {
   "role": "Parts that fit it",
   "items": [
    {
     "slug": "flywheel-disc-hub",
     "why": "Ø15 / Ø25 spigot in the disc's centre hole"
    }
   ]
  },
  {
   "role": "Goes in or on",
   "items": [
    {
     "slug": "can-engine-cap",
     "why": "Ø15 hole on the hub's Ø15.0 spigot"
    }
   ]
  },
  {
   "role": "Connects to",
   "items": [
    {
     "slug": "bamboo-skewers",
     "why": "hub carries the disc on a Ø3 shaft"
    }
   ]
  },
  {
   "role": "Alternatives",
   "items": [
    {
     "slug": "hdd-platters",
     "why": "heavier, flatter Ø95 / Ø65 discs"
    },
    {
     "slug": "crank-discs-5mm-bore",
     "why": "a drawn flywheel instead of a found disc"
    }
   ]
  }
 ],
 "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 is the diameter of a CD centre hole?",
   "a": "15.0 mm (+0.1); the disc is Ø120 × 1.2 mm."
  },
  {
   "q": "Is a DVD the same size as a CD?",
   "a": "Yes: Ø120 × 1.2 mm with a Ø15 hole; Blu-ray too."
  },
  {
   "q": "How big is a mini CD?",
   "a": "Ø80 × 1.2 mm with the same Ø15 centre hole."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "cd-dvd-120",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/cd-dvd-and-drive-platters/cd-dvd-120.step",
   "stl": "https://xemstudio.com/files/hardware/cd-dvd-and-drive-platters/cd-dvd-120.stl",
   "note": "CD / DVD / Blu-ray: Ø120 × 1.2, Ø15 hole (Ø15.0 +0.1)"
  },
  {
   "file": "mini-cd-80",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/cd-dvd-and-drive-platters/mini-cd-80.step",
   "stl": "https://xemstudio.com/files/hardware/cd-dvd-and-drive-platters/mini-cd-80.stl",
   "note": "Mini CD: Ø80 × 1.2, Ø15 hole"
  }
 ],
 "markdown": "https://xemstudio.com/objects/cd-dvd-discs/index.md"
}