{
 "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": "pin-gauges",
 "name": "Printed pin gauges 2.8–3.2 and 4.8–5.2 mm",
 "kind": "hardware",
 "category": "Stirling engines",
 "group": "Generators & instruments",
 "year": null,
 "question": "How much over size do printed pins come out?",
 "tags": [
  "calibration",
  "gauge",
  "pin",
  "tolerance",
  "test print",
  "stirling",
  "long earth society"
 ],
 "aliases": [
  "pin tolerance test print",
  "printed pin calibration",
  "3d print shaft size test",
  "623 bearing fit test",
  "spigot tolerance"
 ],
 "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/pin-gauges/",
 "sheet_txt": "https://xemstudio.com/objects/pin-gauges/sheet.txt",
 "sheet": {
  "basis": "Pins stepped around Ø3 and Ø5 in 0.1 mm steps, tested in the bore of a 623 (Ø3) or 625 (Ø5) bearing",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "Every file on this site is drawn at exact size with no printing allowance; this gauge steps through sizes around the nominal so you can measure the allowance your process needs for one fit class, then apply it only to the features each object lists under Mating features.",
   "Each gauge is a 66 × 16 × 3 mm base with five pins 12 mm tall, 0.3 mm chamfered tips: Ø2.8, 2.9, 3.0, 3.1, 3.2 or Ø4.8, 4.9, 5.0, 5.1, 5.2.",
   "Try each pin in the bore of a 623 (Ø3) or 625 (Ø5) bearing: the pin that enters finger-tight, minus 3.0 or 5.0, is the allowance for printed pins and spigots (usually negative)."
  ],
  "table": {
   "columns": [
    "gauge",
    "pins_mm",
    "test_in"
   ],
   "rows": [
    [
     "pin-gauge-2-8-to-3-2",
     "2.8 / 2.9 / 3.0 / 3.1 / 3.2",
     "623 bore Ø3"
    ],
    [
     "pin-gauge-4-8-to-5-2",
     "4.8 / 4.9 / 5.0 / 5.1 / 5.2",
     "625 bore Ø5"
    ]
   ]
  }
 },
 "sheet_text": "Printed pin gauges 2.8–3.2 and 4.8–5.2 mm — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/pin-gauges/  (CC BY 4.0)\nBasis: Pins stepped around Ø3 and Ø5 in 0.1 mm steps, tested in the bore of a 623 (Ø3) or 625 (Ø5) bearing\nCatalog version: 2026-10-20\n\nSizes: see table below\n- Every file on this site is drawn at exact size with no printing allowance; this gauge steps through sizes around the nominal so you can measure the allowance your process needs for one fit class, then apply it only to the features each object lists under Mating features.\n- Each gauge is a 66 × 16 × 3 mm base with five pins 12 mm tall, 0.3 mm chamfered tips: Ø2.8, 2.9, 3.0, 3.1, 3.2 or Ø4.8, 4.9, 5.0, 5.1, 5.2.\n- Try each pin in the bore of a 623 (Ø3) or 625 (Ø5) bearing: the pin that enters finger-tight, minus 3.0 or 5.0, is the allowance for printed pins and spigots (usually negative).\n\ngauge  pins_mm  test_in\npin-gauge-2-8-to-3-2  2.8 / 2.9 / 3.0 / 3.1 / 3.2  623 bore Ø3\npin-gauge-4-8-to-5-2  4.8 / 4.9 / 5.0 / 5.1 / 5.2  625 bore Ø5\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Wikipedia: Engineering tolerance — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Engineering_tolerance\n- Prusa: Knowledge base: XY size compensation — web — Prusa KB [verify license at link] — https://help.prusa3d.com/article/xy-size-compensation_125045\n- Long Earth Society: Engine and rig builds — 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/pin-gauges/index.json\nAPI: https://xemstudio.com/api/geometry?object=pin-gauges\n",
 "sources": [
  {
   "publisher": "Wikipedia",
   "title": "Engineering tolerance",
   "url": "https://en.wikipedia.org/wiki/Engineering_tolerance",
   "formats": [
    "web"
   ],
   "license": "CC BY-SA 4.0 (text)",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Prusa",
   "title": "Knowledge base: XY size compensation",
   "url": "https://help.prusa3d.com/article/xy-size-compensation_125045",
   "formats": [
    "web"
   ],
   "license": "Prusa KB",
   "license_verified": false,
   "hosted": false
  },
  {
   "publisher": "Long Earth Society",
   "title": "Engine and rig builds",
   "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": [
  "hole-gauges",
  "bearing-pocket-gauge",
  "ball-bearings-metric"
 ],
 "fits": [
  {
   "role": "Connects to",
   "items": [
    {
     "slug": "ball-bearings-metric",
     "why": "pins tried in the Ø3 / Ø5 bore of a 623 / 625"
    }
   ]
  },
  {
   "role": "Also needed",
   "items": [
    {
     "slug": "hole-gauges",
     "why": "the matching inside-diameter test"
    }
   ]
  }
 ],
 "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": [
  {
   "feature": "gauge sizes",
   "exact": "stepped around nominal",
   "mates": "the true pin, nut, bearing or extrusion slot being tested",
   "fit": "designed",
   "files": "all"
  }
 ],
 "fit_classes": {
  "press": "stays put: pin, tube, bearing or magnet held by interference. Typical FDM: hole +0.0 to +0.1 mm on diameter.",
  "slide": "assembles by hand and is held by a grub, pinch or clamp: shaft in a hub, rod in a socket, spigot in a bore. Typical FDM: +0.2 mm.",
  "run": "turns or slides in use: pin in a link, rod through a guide. Typical FDM: +0.3 mm.",
  "socket": "large sliding fit: syringe barrel, sleeve, bobbin in a bore. Typical FDM: +0.3 mm.",
  "clamp": "split part that closes on the mating part with screws: make it at size.",
  "designed": "a gap that is part of the design (piston fit option, displacer gap, air gap): do not change."
 },
 "faq": [
  {
   "q": "Why do printed pins come out over size?",
   "a": "Outside features come out fat for the same reasons holes come out small; the pin gauge measures the outside error."
  },
  {
   "q": "How do I read the pin gauge?",
   "a": "The pin that enters a true Ø3 or Ø5 bearing bore finger-tight, minus the nominal, is your pin allowance."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "pin-gauge-2-8-to-3-2",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/printer-calibration-coupons/pin-gauge-2-8-to-3-2.step",
   "stl": "https://xemstudio.com/files/hardware/printer-calibration-coupons/pin-gauge-2-8-to-3-2.stl",
   "note": "printed pin gauge 2.8–3.2: which prints to a true Ø3 hole in a bearing?"
  },
  {
   "file": "pin-gauge-4-8-to-5-2",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/printer-calibration-coupons/pin-gauge-4-8-to-5-2.step",
   "stl": "https://xemstudio.com/files/hardware/printer-calibration-coupons/pin-gauge-4-8-to-5-2.stl",
   "note": "printed pin gauge 4.8–5.2 (625 bearing bore test)"
  }
 ],
 "markdown": "https://xemstudio.com/objects/pin-gauges/index.md"
}