{
 "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": "pins-clevises-and-joints",
 "name": "Clevis pins, R-clips, cotter pins, clevises, universal joint, rod ends (heim joints)",
 "kind": "hardware",
 "category": "Hardware",
 "group": "Motion",
 "year": null,
 "question": "What size clevis pin and R-clip for a 3D printed linkage?",
 "tags": [
  "pin",
  "clevis",
  "r-clip",
  "cotter",
  "universal joint",
  "rod end",
  "heim joint",
  "linkage",
  "stirling",
  "long earth society"
 ],
 "aliases": [
  "clevis pin sizes",
  "r clip sizes",
  "cotter pin dimensions",
  "clevis 3d print",
  "universal joint stl",
  "rod end m5 dimensions",
  "heim joint sizes",
  "linkage pins"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": true,
 "free_files": 23,
 "url": "https://xemstudio.com/objects/pins-clevises-and-joints/",
 "sheet_txt": "https://xemstudio.com/objects/pins-clevises-and-joints/sheet.txt",
 "sheet": {
  "basis": "ISO 2341 clevis pins, DIN 11024 R-clips, common rod-end (POS/PHS series) ball sizes; printed clevises and a universal joint sized to Ø3/Ø5 pins",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "Clevis pin: plain shank with a head and a cross-hole; Ø3 × 12–20, Ø5 × 20–30, Ø8 × 40 cover model work. Printed hole Ø+0.2 for a pivot, Ø−0.05 press in the fixed side. R-clip (hairpin) sizes by pin: 2–3 mm pin → size 2; 4–5 → size 3–4; 6–8 → size 5. Cotter pins (split pins) Ø1.6 × 16 and Ø2 × 20 for the same holes.",
   "Clevis: fork with a pin across the gap; gap = link thickness + 0.4. The printed ones take an M3 pushrod in the shank. A clevis + pin + R-clip is the field-serviceable joint: no tools.",
   "Universal joint: two yokes and a cross spider on Ø3 pins; transmits rotation across up to 25° with velocity ripple (use two, phased, for constant velocity). Ø14 printed yokes on Ø5 shafts.",
   "Rod ends (heim joints): M3 (ball Ø6), M4 (Ø8), M5 (Ø10), M6 (Ø12), M8 (Ø16) threaded shank, ±13° misalignment; the envelopes here are for fit; buy the steel part (POSA/PHSA series). Male on the rod, female (PHS) takes a bolt through the ball."
  ],
  "table": {
   "columns": [
    "part",
    "sizes",
    "mating hole",
    "note"
   ],
   "rows": [
    [
     "clevis pin",
     "Ø3, 4, 5, 6, 8 × 12–40",
     "Ø + 0.2 pivot / − 0.05 press",
     "ISO 2341"
    ],
    [
     "R-clip",
     "sizes 2–5",
     "cross-hole Ø1–1.6",
     "DIN 11024"
    ],
    [
     "cotter pin",
     "Ø1.6 × 16, Ø2 × 20",
     "Ø1.8 / 2.2",
     "ISO 1234"
    ],
    [
     "clevis (printed)",
     "Ø3 pin gap 5/8, Ø5 gap 8/10, Ø6 gap 12",
     "M3 shank",
     "—"
    ],
    [
     "universal joint",
     "Ø14 yokes, Ø5 shafts",
     "Ø3 cross pins",
     "25° max"
    ],
    [
     "rod end",
     "M3–M8, ball Ø6–16",
     "bolt through ball",
     "POS/PHS series"
    ]
   ]
  }
 },
 "sheet_text": "Clevis pins, R-clips, cotter pins, clevises, universal joint, rod ends (heim joints) — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/pins-clevises-and-joints/  (CC BY 4.0)\nBasis: ISO 2341 clevis pins, DIN 11024 R-clips, common rod-end (POS/PHS series) ball sizes; printed clevises and a universal joint sized to Ø3/Ø5 pins\nCatalog version: 2026-10-20\n\nSizes: see table below\n- Clevis pin: plain shank with a head and a cross-hole; Ø3 × 12–20, Ø5 × 20–30, Ø8 × 40 cover model work. Printed hole Ø+0.2 for a pivot, Ø−0.05 press in the fixed side. R-clip (hairpin) sizes by pin: 2–3 mm pin → size 2; 4–5 → size 3–4; 6–8 → size 5. Cotter pins (split pins) Ø1.6 × 16 and Ø2 × 20 for the same holes.\n- Clevis: fork with a pin across the gap; gap = link thickness + 0.4. The printed ones take an M3 pushrod in the shank. A clevis + pin + R-clip is the field-serviceable joint: no tools.\n- Universal joint: two yokes and a cross spider on Ø3 pins; transmits rotation across up to 25° with velocity ripple (use two, phased, for constant velocity). Ø14 printed yokes on Ø5 shafts.\n- Rod ends (heim joints): M3 (ball Ø6), M4 (Ø8), M5 (Ø10), M6 (Ø12), M8 (Ø16) threaded shank, ±13° misalignment; the envelopes here are for fit; buy the steel part (POSA/PHSA series). Male on the rod, female (PHS) takes a bolt through the ball.\n\npart  sizes  mating hole  note\nclevis pin  Ø3, 4, 5, 6, 8 × 12–40  Ø + 0.2 pivot / − 0.05 press  ISO 2341\nR-clip  sizes 2–5  cross-hole Ø1–1.6  DIN 11024\ncotter pin  Ø1.6 × 16, Ø2 × 20  Ø1.8 / 2.2  ISO 1234\nclevis (printed)  Ø3 pin gap 5/8, Ø5 gap 8/10, Ø6 gap 12  M3 shank  —\nuniversal joint  Ø14 yokes, Ø5 shafts  Ø3 cross pins  25° max\nrod end  M3–M8, ball Ø6–16  bolt through ball  POS/PHS series\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, 23 parts): https://xemstudio.com/files/hardware/pins-clevises-and-joints/index.json\nAPI: https://xemstudio.com/api/geometry?object=pins-clevises-and-joints\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,
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  "tolerance_mm": null
 },
 "related": [
  "motion-mechanisms",
  "dowel-pins-metric",
  "crank-conrod-flywheel-kit",
  "shaft-collars-clips-and-shafts",
  "springs"
 ],
 "faq": [
  {
   "q": "What clevis pin size for a model linkage?",
   "a": "Ø3 mm pins (with size-2 R-clips) for printed links up to 10 mm thick; Ø5 for anything carrying a flywheel load. Pivot holes at Ø3.2 / Ø5.2."
  },
  {
   "q": "What are M5 rod end dimensions?",
   "a": "Ball bore 5 mm, ball Ø10, head about Ø14 × 8 mm thick, M5 shank 20 mm; ±13° of misalignment."
  },
  {
   "q": "How much angle can a universal joint take?",
   "a": "Single joint: 25° with speed ripple; two joints with parallel yokes cancel the ripple (constant velocity) at the same angle."
  }
 ],
 "files_license": null,
 "offers": [
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   "stl": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/clevis-pin-3x12.stl",
   "note": "clevis pin Ø3 × 12 with head and cross-hole for an R-clip"
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   "stl": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/clevis-pin-3x20.stl",
   "note": "clevis pin Ø3 × 20 with head and cross-hole for an R-clip"
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  {
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   "stl": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/clevis-pin-4x20.stl",
   "note": "clevis pin Ø4 × 20 with head and cross-hole for an R-clip"
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   "stl": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/clevis-pin-5x20.stl",
   "note": "clevis pin Ø5 × 20 with head and cross-hole for an R-clip"
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  {
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   "stl": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/clevis-pin-5x30.stl",
   "note": "clevis pin Ø5 × 30 with head and cross-hole for an R-clip"
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   "note": "clevis pin Ø6 × 30 with head and cross-hole for an R-clip"
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   "stl": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/clevis-pin-8x40.stl",
   "note": "clevis pin Ø8 × 40 with head and cross-hole for an R-clip"
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  {
   "file": "r-clip-2",
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   "stl": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/r-clip-2.stl",
   "note": "R-clip (hairpin cotter) for a Ø2–3 pin"
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  {
   "file": "r-clip-3",
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   "stl": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/r-clip-3.stl",
   "note": "R-clip (hairpin cotter) for a Ø3–4 pin"
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   "stl": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/r-clip-4.stl",
   "note": "R-clip (hairpin cotter) for a Ø4–5 pin"
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  {
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   "stl": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/r-clip-5.stl",
   "note": "R-clip (hairpin cotter) for a Ø5–6 pin"
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  {
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   "note": "printed clevis for a Ø3 pin, 5 mm gap, M3 rod"
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   "stl": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/clevis-3-gap8.stl",
   "note": "printed clevis for a Ø3 pin, 8 mm gap, M3 rod"
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   "stl": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/clevis-5-gap8.stl",
   "note": "printed clevis for a Ø5 pin, 8 mm gap, M3 rod"
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   "note": "printed clevis for a Ø5 pin, 10 mm gap, M3 rod"
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   "note": "printed clevis for a Ø6 pin, 12 mm gap, M3 rod"
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   "stl": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/ujoint-yoke-5mm.stl",
   "note": "universal joint yoke Ø14, Ø5 bore, Ø3 cross pins (print two)"
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  {
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   "note": "universal joint spider for the Ø14 yokes, Ø3 pins"
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  {
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   "note": "rod end (heim joint) envelope M3: ball bore 3, ball Ø6, head OD +4"
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   "stl": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/rod-end-m4.stl",
   "note": "rod end (heim joint) envelope M4: ball bore 4, ball Ø8, head OD +4"
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   "stl": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/rod-end-m5.stl",
   "note": "rod end (heim joint) envelope M5: ball bore 5, ball Ø10, head OD +4"
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   "file": "rod-end-m6",
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   "note": "rod end (heim joint) envelope M6: ball bore 6, ball Ø12, head OD +4"
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  {
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   "stl": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/rod-end-m8.stl",
   "note": "rod end (heim joint) envelope M8: ball bore 8, ball Ø16, head OD +4"
  }
 ],
 "markdown": "https://xemstudio.com/objects/pins-clevises-and-joints/index.md"
}