{
 "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": "camera-thread-bosses-1-4-20",
 "name": "Camera tripod thread bosses: 1/4-20 UNC and 3/8-16 UNC",
 "kind": "hardware",
 "category": "Everyday mounts",
 "group": "Adapter blocks",
 "year": null,
 "question": "What thread is a camera tripod screw?",
 "tags": [
  "tripod",
  "camera",
  "1/4-20",
  "3/8-16",
  "thread",
  "mount",
  "adapter"
 ],
 "aliases": [
  "tripod screw size",
  "1/4-20 camera thread",
  "camera mount thread",
  "3/8-16 tripod",
  "1/4-20 boss step",
  "tripod thread hole size",
  "iso 1222"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 2,
 "url": "https://xemstudio.com/objects/camera-thread-bosses-1-4-20/",
 "sheet_txt": "https://xemstudio.com/objects/camera-thread-bosses-1-4-20/sheet.txt",
 "sheet": {
  "basis": "DIN 4503-1 / ISO 1222 tripod threads as given by Threading Tools Guide: 1/4-20 UNC (major Ø6.35, core hole Ø5.35) and 3/8-16 UNC (major Ø9.52, core hole Ø8.25)",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "Cameras, phone clamps, lights and small tripod heads take a 1/4-20 UNC screw; larger heads and most tripod-to-head joints use 3/8-16 UNC. Both are 60° Unified threads.",
   "Files: a round boss for each with a blind hole at the published core-hole diameter, to cut the internal thread into or to fit a threaded insert of your choice. The boss Ø, height and hole depth are my design.",
   "The screw side is in the catalog: 1/4-20 socket head cap screws in imperial-machine-screws.",
   "Arca-Swiss style dovetails are not drawn: there is no published standard; makers' plates measure 38.0 to 38.75 mm across."
  ],
  "table": {
   "columns": [
    "thread",
    "major Ø (mm)",
    "core hole Ø (mm)",
    "boss (my design)",
    "from"
   ],
   "rows": [
    [
     "1/4-20 UNC",
     "6.35",
     "5.35",
     "Ø16 × 10, hole 8 deep",
     "DIN 4503-1 / ISO 1222 (Threading Tools Guide)"
    ],
    [
     "3/8-16 UNC",
     "9.52",
     "8.25",
     "Ø22 × 12, hole 10 deep",
     "DIN 4503-1 / ISO 1222 (Threading Tools Guide)"
    ]
   ]
  }
 },
 "sheet_text": "Camera tripod thread bosses: 1/4-20 UNC and 3/8-16 UNC — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/camera-thread-bosses-1-4-20/  (CC BY 4.0)\nBasis: DIN 4503-1 / ISO 1222 tripod threads as given by Threading Tools Guide: 1/4-20 UNC (major Ø6.35, core hole Ø5.35) and 3/8-16 UNC (major Ø9.52, core hole Ø8.25)\nCatalog version: 2026-10-20\n\nSizes: see table below\n- Cameras, phone clamps, lights and small tripod heads take a 1/4-20 UNC screw; larger heads and most tripod-to-head joints use 3/8-16 UNC. Both are 60° Unified threads.\n- Files: a round boss for each with a blind hole at the published core-hole diameter, to cut the internal thread into or to fit a threaded insert of your choice. The boss Ø, height and hole depth are my design.\n- The screw side is in the catalog: 1/4-20 socket head cap screws in imperial-machine-screws.\n- Arca-Swiss style dovetails are not drawn: there is no published standard; makers' plates measure 38.0 to 38.75 mm across.\n\nthread  major Ø (mm)  core hole Ø (mm)  boss (my design)  from\n1/4-20 UNC  6.35  5.35  Ø16 × 10, hole 8 deep  DIN 4503-1 / ISO 1222 (Threading Tools Guide)\n3/8-16 UNC  9.52  8.25  Ø22 × 12, hole 10 deep  DIN 4503-1 / ISO 1222 (Threading Tools Guide)\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Threading Tools Guide: Tripod thread DIN 4503-1 / ISO 1222: 1/4-20 UNC (Ø6.35, core hole Ø5.35) and 3/8-16 UNC (Ø9.52, core hole Ø8.25) — web — reference [verify license at link] — https://threadingtoolsguide.com/en/blog/tripod-thread-din-4503-1-iso-1222/\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 2 parts): https://xemstudio.com/files/hardware/camera-thread-bosses-1-4-20/index.json\nAPI: https://xemstudio.com/api/geometry?object=camera-thread-bosses-1-4-20\n",
 "sources": [
  {
   "publisher": "Threading Tools Guide",
   "title": "Tripod thread DIN 4503-1 / ISO 1222: 1/4-20 UNC (Ø6.35, core hole Ø5.35) and 3/8-16 UNC (Ø9.52, core hole Ø8.25)",
   "url": "https://threadingtoolsguide.com/en/blog/tripod-thread-din-4503-1-iso-1222/",
   "formats": [
    "web"
   ],
   "license": "reference",
   "license_verified": false,
   "hosted": false
  }
 ],
 "xem": {
  "status": "free-files",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "imperial-machine-screws",
  "handlebar-clamp-rings",
  "phone-mount-ball-17mm",
  "gopro-mount"
 ],
 "fits": [
  {
   "role": "Goes in or on",
   "items": [
    {
     "slug": "handlebar-clamp-rings",
     "why": "a boss unioned onto a bar clamp"
    }
   ]
  },
  {
   "role": "Connects to",
   "items": [
    {
     "slug": "imperial-machine-screws",
     "why": "1/4-20 screw into the boss"
    }
   ]
  },
  {
   "role": "Alternatives",
   "items": [
    {
     "slug": "gopro-mount",
     "why": "three-finger action-camera mount"
    }
   ]
  }
 ],
 "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": "core hole",
   "exact": "Ø5.35 (1/4-20 UNC) / Ø8.25 (3/8-16 UNC)",
   "mates": "internal thread cut to the screw (DIN 4503-1 / ISO 1222)",
   "fit": "designed",
   "files": "camera-boss-"
  }
 ],
 "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 thread is a camera tripod screw?",
   "a": "1/4-20 UNC on cameras and small accessories, 3/8-16 UNC on larger heads and tripods (DIN 4503-1 / ISO 1222)."
  },
  {
   "q": "What hole size for a 1/4-20 thread?",
   "a": "Core hole Ø5.35 mm per DIN 4503-1 as given by Threading Tools Guide; the major diameter is 6.35 mm."
  },
  {
   "q": "Is there a standard Arca-Swiss plate drawing?",
   "a": "No published standard; plates measure 38.0–38.75 mm across the dovetail, so none is drawn here."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "camera-boss-1-4-20",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/camera-thread-bosses-1-4-20/camera-boss-1-4-20.step",
   "stl": "https://xemstudio.com/files/hardware/camera-thread-bosses-1-4-20/camera-boss-1-4-20.stl",
   "note": "1/4-20 UNC boss: Ø16 × 10 (my size), blind core hole Ø5.35 × 8 deep from the top face for the 1/4-20 UNC internal thread (major Ø6.35)"
  },
  {
   "file": "camera-boss-3-8-16",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/camera-thread-bosses-1-4-20/camera-boss-3-8-16.step",
   "stl": "https://xemstudio.com/files/hardware/camera-thread-bosses-1-4-20/camera-boss-3-8-16.stl",
   "note": "3/8-16 UNC boss: Ø22 × 12 (my size), blind core hole Ø8.25 × 10 deep from the top face for the 3/8-16 UNC internal thread (major Ø9.52)"
  }
 ],
 "markdown": "https://xemstudio.com/objects/camera-thread-bosses-1-4-20/index.md"
}