{
 "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": "r-clips",
 "name": "R-clips (hairpin cotters) for Ø2 to Ø6 pins",
 "kind": "hardware",
 "category": "Hardware",
 "group": "Motion",
 "year": null,
 "question": "What size R-clip fits a given pin diameter?",
 "tags": [
  "r-clip",
  "hairpin",
  "cotter",
  "pin retainer",
  "linkage",
  "stirling",
  "long earth society"
 ],
 "aliases": [
  "r clip sizes",
  "hairpin cotter pin dimensions",
  "r clip for 5mm pin",
  "r clip stl",
  "beta pin dimensions"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": true,
 "free_files": 5,
 "url": "https://xemstudio.com/objects/r-clips/",
 "sheet_txt": "https://xemstudio.com/objects/r-clips/sheet.txt",
 "sheet": {
  "basis": "Hairpin R-clip envelopes scaled to the pin Ø: straight leg 6 × pin Ø, loop OD 3.2 × pin Ø, 1.2 wire",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "A hairpin clip: one straight leg goes through the pin's cross-hole and the curved leg wraps over the pin to hold it. All four files have a 1.2 mm wire, drawn flat (1.2 thick).",
   "Overall length and loop OD: r-clip-2 14.2 × 6.4; r-clip-3 21.3 × 9.6; r-clip-4 28.4 × 12.8; r-clip-5 35.5 × 16.0. The number in the file name is the smallest pin Ø it is drawn for; each covers that Ø and the next millimetre up.",
   "The 1.2 wire passes cross-holes of Ø1.2 and larger: the Ø5, Ø6 and Ø8 clevis pins (Ø1.2, Ø1.6, Ø2.0 holes)."
  ],
  "table": {
   "columns": [
    "file",
    "pin Ø",
    "wire Ø",
    "length",
    "loop OD"
   ],
   "rows": [
    [
     "r-clip-3",
     "2–3",
     1.2,
     14.2,
     6.4
    ],
    [
     "r-clip-3",
     "3–4",
     1.2,
     21.3,
     9.6
    ],
    [
     "r-clip-4",
     "4–5",
     1.2,
     28.4,
     12.8
    ],
    [
     "r-clip-5",
     "5–6",
     1.2,
     35.5,
     16
    ]
   ]
  }
 },
 "sheet_text": "R-clips (hairpin cotters) for Ø2 to Ø6 pins — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/r-clips/  (CC BY 4.0)\nBasis: Hairpin R-clip envelopes scaled to the pin Ø: straight leg 6 × pin Ø, loop OD 3.2 × pin Ø, 1.2 wire\nCatalog version: 2026-10-20\n\nSizes: see table below\n- A hairpin clip: one straight leg goes through the pin's cross-hole and the curved leg wraps over the pin to hold it. All four files have a 1.2 mm wire, drawn flat (1.2 thick).\n- Overall length and loop OD: r-clip-2 14.2 × 6.4; r-clip-3 21.3 × 9.6; r-clip-4 28.4 × 12.8; r-clip-5 35.5 × 16.0. The number in the file name is the smallest pin Ø it is drawn for; each covers that Ø and the next millimetre up.\n- The 1.2 wire passes cross-holes of Ø1.2 and larger: the Ø5, Ø6 and Ø8 clevis pins (Ø1.2, Ø1.6, Ø2.0 holes).\n\nfile  pin Ø  wire Ø  length  loop OD\nr-clip-3  2–3  1.2  14.2  6.4\nr-clip-3  3–4  1.2  21.3  9.6\nr-clip-4  4–5  1.2  28.4  12.8\nr-clip-5  5–6  1.2  35.5  16.0\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Wikipedia: Clevis fastener — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Clevis_fastener\n- Wikipedia: Universal joint — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Universal_joint\n- Wikipedia: Rod end bearing — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Rod_end_bearing\n- McMaster-Carr: Clevis pins (free STEP per part, for your own design use; no redistribution) — STEP, PDF — McMaster-Carr site terms [verify license at link] — https://www.mcmaster.com/products/clevis-pins/\n- McMaster-Carr: Rod ends (free STEP per part, for your own design use; no redistribution) — STEP, PDF — McMaster-Carr site terms [verify license at link] — https://www.mcmaster.com/products/ball-joint-rod-ends/\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, 5 parts): https://xemstudio.com/files/hardware/r-clips/index.json\nAPI: https://xemstudio.com/api/geometry?object=r-clips\n",
 "sources": [
  {
   "publisher": "Wikipedia",
   "title": "Clevis fastener",
   "url": "https://en.wikipedia.org/wiki/Clevis_fastener",
   "formats": [
    "web"
   ],
   "license": "CC BY-SA 4.0 (text)",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Wikipedia",
   "title": "Universal joint",
   "url": "https://en.wikipedia.org/wiki/Universal_joint",
   "formats": [
    "web"
   ],
   "license": "CC BY-SA 4.0 (text)",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Wikipedia",
   "title": "Rod end bearing",
   "url": "https://en.wikipedia.org/wiki/Rod_end_bearing",
   "formats": [
    "web"
   ],
   "license": "CC BY-SA 4.0 (text)",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "McMaster-Carr",
   "title": "Clevis pins (free STEP per part, for your own design use; no redistribution)",
   "url": "https://www.mcmaster.com/products/clevis-pins/",
   "formats": [
    "STEP",
    "PDF"
   ],
   "license": "McMaster-Carr site terms",
   "license_verified": false,
   "hosted": false
  },
  {
   "publisher": "McMaster-Carr",
   "title": "Rod ends (free STEP per part, for your own design use; no redistribution)",
   "url": "https://www.mcmaster.com/products/ball-joint-rod-ends/",
   "formats": [
    "STEP",
    "PDF"
   ],
   "license": "McMaster-Carr site terms",
   "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": [
  "clevis-pins",
  "clevises",
  "dowel-pins-metric"
 ],
 "fits": [
  {
   "role": "Goes in or on",
   "items": [
    {
     "slug": "clevis-pins",
     "why": "1.2 wire through the pin's cross-hole"
    }
   ]
  },
  {
   "role": "Connects to",
   "items": [
    {
     "slug": "clevises",
     "why": "holds the pin across the fork"
    }
   ]
  }
 ],
 "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": "R-clip wire",
   "exact": "Ø0.8 / 1.0 / 1.2 / 1.6 / 2.0",
   "mates": "split-pin hole of the Ø3 / 4 / 5 / 6 / 8 clevis pin",
   "fit": "slide",
   "files": "r-clip-"
  }
 ],
 "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 size R-clip for a 5 mm pin?",
   "a": "r-clip-4 (Ø4–5 pins) or r-clip-5 (Ø5–6): 28.4 or 35.5 mm long, 1.2 mm wire, which passes the Ø1.2 cross-hole of an ISO 2341 Ø5 clevis pin."
  },
  {
   "q": "How thick is the R-clip wire?",
   "a": "1.2 mm on all four files."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "r-clip-3",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/r-clip-3.step",
   "stl": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/r-clip-3.stl",
   "note": "R-clip (hairpin) for the Ø3 clevis pins (clevis-pin-3x12, clevis-pin-3x20): wire Ø0.8 = their split-pin hole, straight leg 18 long, bow wraps the Ø3 pin"
  },
  {
   "file": "r-clip-4",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/r-clip-4.step",
   "stl": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/r-clip-4.stl",
   "note": "R-clip (hairpin) for the Ø4 clevis pins (clevis-pin-4x20): wire Ø1 = their split-pin hole, straight leg 24 long, bow wraps the Ø4 pin"
  },
  {
   "file": "r-clip-5",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/r-clip-5.step",
   "stl": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/r-clip-5.stl",
   "note": "R-clip (hairpin) for the Ø5 clevis pins (clevis-pin-5x20, clevis-pin-5x30): wire Ø1.2 = their split-pin hole, straight leg 30 long, bow wraps the Ø5 pin"
  },
  {
   "file": "r-clip-6",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/r-clip-6.step",
   "stl": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/r-clip-6.stl",
   "note": "R-clip (hairpin) for the Ø6 clevis pins (clevis-pin-6x30): wire Ø1.6 = their split-pin hole, straight leg 36 long, bow wraps the Ø6 pin"
  },
  {
   "file": "r-clip-8",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/r-clip-8.step",
   "stl": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/r-clip-8.stl",
   "note": "R-clip (hairpin) for the Ø8 clevis pins (clevis-pin-8x40): wire Ø2 = their split-pin hole, straight leg 48 long, bow wraps the Ø8 pin"
  }
 ],
 "markdown": "https://xemstudio.com/objects/r-clips/index.md"
}