{
 "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": "5-25-inch-floppy-disk-130-mm",
 "name": "5.25 in floppy disk (130 mm minifloppy)",
 "kind": "modern",
 "category": "Vintage forms",
 "group": "Retro media",
 "year": 1985,
 "question": "What are the exact dimensions of a 5.25 inch floppy disk?",
 "tags": [
  "floppy disk",
  "diskette",
  "retro media",
  "vintage computer",
  "storage"
 ],
 "aliases": [
  "5.25 floppy disk dimensions",
  "5 1/4 floppy size mm",
  "minifloppy dimensions",
  "1.2mb floppy size",
  "360k floppy size",
  "disquete 5.25 medidas",
  "disquete 5 1/4 dimensões",
  "Diskette 5,25 Zoll Maße"
 ],
 "overall_mm": {
  "length": 133.3,
  "width": 133.3,
  "height": 2.1
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 1,
 "url": "https://xemstudio.com/objects/5-25-inch-floppy-disk-130-mm/",
 "sheet_txt": "https://xemstudio.com/objects/5-25-inch-floppy-disk-130-mm/sheet.txt",
 "sheet": {
  "basis": "ECMA-99, 130 mm flexible disk cartridge, 1.2 MB high density",
  "overall_mm": {
   "length": 133.3,
   "width": 133.3,
   "height": 2.1
  },
  "notes": [
   "A 5.25 inch floppy disk jacket is a 133.3 mm square (l1 = 133.3 ±0.4 mm, corners 90° ±30′) and between 1.2 and 2.1 mm thick overall (ECMA-99 §3.1). The central window is Ø39.7 ±0.2 mm, centred 66.65 mm from the reference edge — the middle of the jacket.",
   "ECMA-99 is the 1.2 MB high-density disk; the 360 KB double-density disk is specified in ECMA-78. Write-protect notch size is not in this standard's text.",
   "The file is the jacket at the published size: 133.3 × 133.3 mm, drawn 2.1 mm thick (the standard's maximum overall thickness), with the Ø39.7 mm central window at the jacket centre; no printing allowance. Index and head windows are listed above but not modelled. "
  ],
  "table": {
   "columns": [
    "dimension",
    "value"
   ],
   "rows": [
    [
     "jacket side (l1)",
     "133.3 mm ±0.4"
    ],
    [
     "corner angle",
     "90° ±30′"
    ],
    [
     "overall thickness (e2)",
     "over 1.2 mm, under 2.1 mm"
    ],
    [
     "gauge",
     "falls freely through a 2.6 mm slot, 150 mm deep"
    ],
    [
     "central window (d1)",
     "Ø39.7 mm"
    ],
    [
     "central window centre (l2)",
     "66.65 mm ±0.30 from the reference edge"
    ],
    [
     "index window (d2)",
     "Ø6.35 mm ±0.20 at l3 42.10 / l4 60.00 mm ±0.25"
    ],
    [
     "head window",
     "12.7 mm ±0.2 wide × 35.00 mm ±0.25 long, R6.35 ends, lowest point 3.30 mm ±0.25 from the reference edge"
    ],
    [
     "optional notches",
     "inside 48.0 mm min. to 58.0 mm max. along the reference edge"
    ]
   ]
  }
 },
 "sheet_text": "5.25 in floppy disk (130 mm minifloppy) — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/5-25-inch-floppy-disk-130-mm/  (CC BY 4.0)\nBasis: ECMA-99, 130 mm flexible disk cartridge, 1.2 MB high density\nCatalog version: 2026-10-20\n\nOverall (mm): length 133.3, width 133.3, height 2.1\n- A 5.25 inch floppy disk jacket is a 133.3 mm square (l1 = 133.3 ±0.4 mm, corners 90° ±30′) and between 1.2 and 2.1 mm thick overall (ECMA-99 §3.1). The central window is Ø39.7 ±0.2 mm, centred 66.65 mm from the reference edge — the middle of the jacket.\n- ECMA-99 is the 1.2 MB high-density disk; the 360 KB double-density disk is specified in ECMA-78. Write-protect notch size is not in this standard's text.\n- The file is the jacket at the published size: 133.3 × 133.3 mm, drawn 2.1 mm thick (the standard's maximum overall thickness), with the Ø39.7 mm central window at the jacket centre; no printing allowance. Index and head windows are listed above but not modelled. \n\ndimension  value\njacket side (l1)  133.3 mm ±0.4\ncorner angle  90° ±30′\noverall thickness (e2)  over 1.2 mm, under 2.1 mm\ngauge  falls freely through a 2.6 mm slot, 150 mm deep\ncentral window (d1)  Ø39.7 mm\ncentral window centre (l2)  66.65 mm ±0.30 from the reference edge\nindex window (d2)  Ø6.35 mm ±0.20 at l3 42.10 / l4 60.00 mm ±0.25\nhead window  12.7 mm ±0.2 wide × 35.00 mm ±0.25 long, R6.35 ends, lowest point 3.30 mm ±0.25 from the reference edge\noptional notches  inside 48.0 mm min. to 58.0 mm max. along the reference edge\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Ecma International: ECMA-99 (PDF) — web — Publisher's page; dimensions are facts — https://ecma-international.org/wp-content/uploads/ECMA-99_1st_edition_september_1985.pdf\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/5-25-inch-floppy-disk-130-mm/index.json\nAPI: https://xemstudio.com/api/geometry?object=5-25-inch-floppy-disk-130-mm\n",
 "sources": [
  {
   "publisher": "Ecma International",
   "title": "ECMA-99 (PDF)",
   "url": "https://ecma-international.org/wp-content/uploads/ECMA-99_1st_edition_september_1985.pdf",
   "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": [
  "3-5-inch-floppy-disk-90-mm",
  "8-inch-floppy-disk-200-mm",
  "cd-dvd-discs"
 ],
 "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": "How big is a 5.25 inch floppy disk?",
   "a": "The jacket is 133.3 mm square and under 2.1 mm thick, with a Ø39.7 mm centre window (ECMA-99)."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "5-25-inch-floppy-disk-130-mm-jacket",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/5-25-inch-floppy-disk-130-mm/5-25-inch-floppy-disk-130-mm-jacket.step",
   "stl": "https://xemstudio.com/files/hardware/5-25-inch-floppy-disk-130-mm/5-25-inch-floppy-disk-130-mm-jacket.stl",
   "note": "Jacket 133.3 mm square × 2.1 mm, Ø39.7 central window (ECMA-99 nominal)"
  }
 ],
 "markdown": "https://xemstudio.com/objects/5-25-inch-floppy-disk-130-mm/index.md"
}