{
 "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": "extrusion-tongue-gauge",
 "name": "T-slot tongue gauge 5.6 / 5.8 / 6.0 mm (6 mm slot)",
 "kind": "hardware",
 "category": "Stirling engines",
 "group": "Generators & instruments",
 "year": null,
 "question": "What tongue width slides in a 2020 extrusion slot when 3D printed?",
 "tags": [
  "calibration",
  "gauge",
  "t-slot",
  "tolerance",
  "extrusion",
  "stirling",
  "long earth society"
 ],
 "aliases": [
  "t slot tongue tolerance",
  "2020 slot fit test",
  "extrusion tongue gauge",
  "6mm slot test print",
  "t-nut tolerance test"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": true,
 "free_files": 1,
 "url": "https://xemstudio.com/objects/extrusion-tongue-gauge/",
 "sheet_txt": "https://xemstudio.com/objects/extrusion-tongue-gauge/sheet.txt",
 "sheet": {
  "basis": "Tongues stepped below the 6.0 mm slot opening of 20-series extrusion",
  "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.",
   "The gauge is a 60 × 30 × 3 mm plate with three tongues 20 mm long × 1.5 mm tall, 5.6, 5.8 and 6.0 mm wide, on 20 mm pitch.",
   "Slide each tongue into the slot of a 6 mm-slot extrusion: the widest one that slides, minus 6.0, is your tongue allowance (negative)."
  ],
  "table": {
   "columns": [
    "tongue",
    "width_mm",
    "length_mm",
    "height_mm"
   ],
   "rows": [
    [
     "1",
     5.6,
     20,
     1.5
    ],
    [
     "2",
     5.8,
     20,
     1.5
    ],
    [
     "3",
     6,
     20,
     1.5
    ]
   ]
  }
 },
 "sheet_text": "T-slot tongue gauge 5.6 / 5.8 / 6.0 mm (6 mm slot) — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/extrusion-tongue-gauge/  (CC BY 4.0)\nBasis: Tongues stepped below the 6.0 mm slot opening of 20-series extrusion\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- The gauge is a 60 × 30 × 3 mm plate with three tongues 20 mm long × 1.5 mm tall, 5.6, 5.8 and 6.0 mm wide, on 20 mm pitch.\n- Slide each tongue into the slot of a 6 mm-slot extrusion: the widest one that slides, minus 6.0, is your tongue allowance (negative).\n\ntongue  width_mm  length_mm  height_mm\n1  5.6  20  1.5\n2  5.8  20  1.5\n3  6.0  20  1.5\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, 1 parts): https://xemstudio.com/files/hardware/extrusion-tongue-gauge/index.json\nAPI: https://xemstudio.com/api/geometry?object=extrusion-tongue-gauge\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": [
  "2020-extrusion",
  "slide-in-t-nuts",
  "t-slot-extrusions",
  "hole-gauges"
 ],
 "fits": [
  {
   "role": "Goes in or on",
   "items": [
    {
     "slug": "2020-extrusion",
     "why": "tongues slide in the 6.0 mm slot opening"
    }
   ]
  },
  {
   "role": "Connects to",
   "items": [
    {
     "slug": "slide-in-t-nuts",
     "why": "the measured allowance applies to T-nut tongues"
    }
   ]
  }
 ],
 "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": "What width should a tongue be for a 2020 slot?",
   "a": "The slot is 6.0 mm and the tongues are drawn at 6.0; this gauge shows how much narrower your process needs it."
  },
  {
   "q": "Does it work for 30- or 40-series?",
   "a": "No; it is sized for the 6 mm slot of 20-series extrusion."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "extrusion-tongue-gauge-6mm",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/printer-calibration-coupons/extrusion-tongue-gauge-6mm.step",
   "stl": "https://xemstudio.com/files/hardware/printer-calibration-coupons/extrusion-tongue-gauge-6mm.stl",
   "note": "T-slot tongue gauge: 5.6 / 5.8 / 6.0 mm tongues for a 6 mm slot"
  }
 ],
 "markdown": "https://xemstudio.com/objects/extrusion-tongue-gauge/index.md"
}