{
 "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": "stirling-conrods-626-625",
 "name": "Con-rods and links with a 626 big end and a 625 small end: 55 to 488 mm",
 "kind": "hardware",
 "category": "Hardware",
 "group": "Stirling & thermoacoustic",
 "year": null,
 "question": "What con-rod carries the load of a charged 48 mm Stirling piston?",
 "tags": [
  "con-rod",
  "connecting rod",
  "tri-clamp",
  "stirling",
  "long earth society"
 ],
 "aliases": [
  "stirling con rod 626",
  "connecting rod ball bearing"
 ],
 "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/stirling-conrods-626-625/",
 "sheet_txt": "https://xemstudio.com/objects/stirling-conrods-626-625/sheet.txt",
 "sheet": {
  "basis": "626 and 625 sizes from their standards; lengths are design values",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "At 5 bar gauge the piston force swings about ±307 N; a 626 big end on a Ø6 crank pin and a 625 small end on the Ø5 wrist pin carry it on ball bearings."
  ],
  "table": {
   "columns": [
    "length_mm",
    "big end",
    "small end"
   ],
   "rows": [
    [
     100,
     "626",
     "625"
    ],
    [
     120,
     "626",
     "625"
    ],
    [
     55,
     "626",
     "625"
    ],
    [
     60,
     "626",
     "625"
    ],
    [
     488.4,
     "626",
     "625"
    ]
   ]
  }
 },
 "sheet_text": "Con-rods and links with a 626 big end and a 625 small end: 55 to 488 mm — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/stirling-conrods-626-625/  (CC BY 4.0)\nBasis: 626 and 625 sizes from their standards; lengths are design values\nCatalog version: 2026-10-20\n\nSizes: see table below\n- At 5 bar gauge the piston force swings about ±307 N; a 626 big end on a Ø6 crank pin and a 625 small end on the Ø5 wrist pin carry it on ball bearings.\n\nlength_mm  big end  small end\n100.0  626  625\n120.0  626  625\n55.0  626  625\n60.0  626  625\n488.4  626  625\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Long Earth Society: Engine 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/stirling-conrods-626-625/index.json\nAPI: https://xemstudio.com/api/geometry?object=stirling-conrods-626-625\n",
 "sources": [
  {
   "publisher": "Long Earth Society",
   "title": "Engine 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": [
  "stirling-crosshead-yokes",
  "stirling-built-up-crank-webs",
  "list-tri-clamp-horizontal-gamma",
  "list-tri-clamp-charged-beta"
 ],
 "fits": [],
 "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": "big end",
   "exact": "Ø19 × 6 pocket, Ø15 lip",
   "mates": "626 bearing OD",
   "fit": "press",
   "files": "all"
  },
  {
   "feature": "small end",
   "exact": "Ø16 × 5 pocket, Ø12 lip",
   "mates": "625 bearing OD",
   "fit": "press",
   "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": "Which engine uses which?",
   "a": "100: both rods of the horizontal gamma and the walking-beam gamma's displacer; 120 and 55: the beta's piston and displacer; 60 and the long link: the walking beam's two links."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "conrod-626-625-100",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/stirling-conrods-626-625/conrod-626-625-100.step",
   "stl": "https://xemstudio.com/files/hardware/stirling-conrods-626-625/conrod-626-625-100.stl",
   "note": "con-rod 100 between eyes, 7 thick: 626 pocket Ø19 × 6 (big end), 625 pocket Ø16 × 5 (small end)"
  },
  {
   "file": "conrod-626-625-120",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/stirling-conrods-626-625/conrod-626-625-120.step",
   "stl": "https://xemstudio.com/files/hardware/stirling-conrods-626-625/conrod-626-625-120.stl",
   "note": "con-rod 120 between eyes, 7 thick: 626 pocket Ø19 × 6 (big end), 625 pocket Ø16 × 5 (small end)"
  },
  {
   "file": "conrod-626-625-55",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/stirling-conrods-626-625/conrod-626-625-55.step",
   "stl": "https://xemstudio.com/files/hardware/stirling-conrods-626-625/conrod-626-625-55.stl",
   "note": "con-rod 55 between eyes, 7 thick: 626 pocket Ø19 × 6 (big end), 625 pocket Ø16 × 5 (small end)"
  },
  {
   "file": "conrod-626-625-60",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/stirling-conrods-626-625/conrod-626-625-60.step",
   "stl": "https://xemstudio.com/files/hardware/stirling-conrods-626-625/conrod-626-625-60.stl",
   "note": "con-rod 60 between eyes, 7 thick: 626 pocket Ø19 × 6 (big end), 625 pocket Ø16 × 5 (small end)"
  },
  {
   "file": "conrod-626-625-488.4",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/stirling-conrods-626-625/conrod-626-625-488.4.step",
   "stl": "https://xemstudio.com/files/hardware/stirling-conrods-626-625/conrod-626-625-488.4.stl",
   "note": "con-rod 488.4 between eyes, 7 thick: 626 pocket Ø19 × 6 (big end), 625 pocket Ø16 × 5 (small end)"
  }
 ],
 "markdown": "https://xemstudio.com/objects/stirling-conrods-626-625/index.md"
}