{
 "version": "2026-10-20",
 "license": "Dimension sheets: CC BY 4.0. Standard and published-size files: CC BY 4.0. Xem Studio's own designs (files_license = Xem Studio Design License): free to use and sell things from, not to redistribute as files — https://xemstudio.com/license/. Other publishers' files: their own license, linked beside them.",
 "slug": "qd-bushings-sh-sds-sd",
 "name": "QD bushings SH, SDS, SD: length, bolt circle, flange diameter and cap screws",
 "kind": "standard",
 "category": "Hardware",
 "group": "Bearings, rails & motion",
 "year": null,
 "question": "What are the dimensions of a QD bushing (SH, SDS, SD): length, bolt circle, flange diameter and cap screw size?",
 "tags": [
  "qd bushing",
  "quick disconnect bushing",
  "sh bushing",
  "sds bushing",
  "sd bushing",
  "bolt circle",
  "flange",
  "sheave",
  "sprocket hub",
  "standard",
  "tool"
 ],
 "aliases": [
  "qd bushing dimensions",
  "sh qd bushing bolt circle",
  "sd qd bushing length",
  "sds bushing dimensions",
  "qd bushing flange diameter",
  "qd bushing bolt circle",
  "qd bushing cap screw size",
  "qd bushing sizes chart",
  "sd bushing 1 3/16 flange",
  "qd vs taper lock"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "not-scanned",
 "les": false,
 "free_files": 0,
 "url": "https://xemstudio.com/objects/qd-bushings-sh-sds-sd/",
 "sheet_txt": "https://xemstudio.com/objects/qd-bushings-sh-sds-sd/sheet.txt",
 "sheet": {
  "basis": "Martin Sprocket catalog E-1 table (length, bolt circle, cap screws) confirmed per size by product pages for SH, SDS and SD; partial by design",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "QD (quick-disconnect) is a split tapered bushing with a flange, held by three or four cap screws on a bolt circle (Martin's table). The bushing letters give the size (JA, SH, SDS, SD, SK, SF, E, F, J, M, N, P, W, S); the hub or sheave must be 'QD' for that bushing, and the bore is chosen per shaft.",
   "Only the three smallest are tabulated, because they are the rows that two sources confirm: Martin's catalog E-1 (page B-4) gives length L and bolt circle; product pages for SH 3/4, SDS 1-5/8 and SD 1-3/16 confirm the bolt circles (2.25, 2.688, 2.687 / 2.688 in), the flange diameters (2.688, 3.188, 3.188 in) and, for SDS (1.375, length through bore) and SD (1.813), the length. SH: Martin L 1.250 against a retailer's overall length of 1-7/32 (1.219): a different length measure; Martin's value is shown.",
   "SDS cap screw: Martin lists 1/4 × 1-3/8 and one product page lists 1/4 × 1-7/8; both are shown (the SD is 1-7/8). Barrel diameter varies with the bore chosen (for example SD 2.187 in on the 1-3/16 bore, SH 1.871 in on the 3/4 bore) so it is not tabulated.",
   "Left out: JA, SK, SF, E, F, J, M, N, P, W and S. The Martin table text was read, but the SK length (1.125 in) is inconsistent with the other rows, SF's retailer length (2-1/16 in) differs from Martin's 2.000 in, and W / S screw entries are garbled, so those rows are not published here. Bore ranges and keyseat sizes per bushing were also not read legibly. Use Martin's, Dodge's or TB Wood's current catalogue for those sizes.",
   "No files: the bushing's taper, flange and barrel profile are not in the tables read, so a bushing file would be invented. For hub design use the maker's CAD (links below)."
  ],
  "table": {
   "columns": [
    "bushing",
    "length L, in (mm)",
    "bolt circle, in (mm)",
    "cap screws (qty × size)",
    "flange Ø, in (mm)"
   ],
   "rows": [
    [
     "SH",
     "1.250 (31.8)",
     "2.250 (57.1)",
     "3 × 1/4-20 × 1-3/8",
     "2.688 (68.3)"
    ],
    [
     "SDS",
     "1.375 (34.9)",
     "2.688 (68.3)",
     "3 × 1/4-20 × 1-3/8 (product page: 1-7/8)",
     "3.188 (81.0)"
    ],
    [
     "SD",
     "1.813 (46.1)",
     "2.688 (68.3)",
     "3 × 1/4-20 × 1-7/8",
     "3.188 (81.0)"
    ]
   ]
  }
 },
 "sheet_text": "QD bushings SH, SDS, SD: length, bolt circle, flange diameter and cap screws — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/qd-bushings-sh-sds-sd/  (sheet CC BY 4.0)\nBasis: Martin Sprocket catalog E-1 table (length, bolt circle, cap screws) confirmed per size by product pages for SH, SDS and SD; partial by design\nCatalog version: 2026-10-20\n\nSizes: see table below\n- QD (quick-disconnect) is a split tapered bushing with a flange, held by three or four cap screws on a bolt circle (Martin's table). The bushing letters give the size (JA, SH, SDS, SD, SK, SF, E, F, J, M, N, P, W, S); the hub or sheave must be 'QD' for that bushing, and the bore is chosen per shaft.\n- Only the three smallest are tabulated, because they are the rows that two sources confirm: Martin's catalog E-1 (page B-4) gives length L and bolt circle; product pages for SH 3/4, SDS 1-5/8 and SD 1-3/16 confirm the bolt circles (2.25, 2.688, 2.687 / 2.688 in), the flange diameters (2.688, 3.188, 3.188 in) and, for SDS (1.375, length through bore) and SD (1.813), the length. SH: Martin L 1.250 against a retailer's overall length of 1-7/32 (1.219): a different length measure; Martin's value is shown.\n- SDS cap screw: Martin lists 1/4 × 1-3/8 and one product page lists 1/4 × 1-7/8; both are shown (the SD is 1-7/8). Barrel diameter varies with the bore chosen (for example SD 2.187 in on the 1-3/16 bore, SH 1.871 in on the 3/4 bore) so it is not tabulated.\n- Left out: JA, SK, SF, E, F, J, M, N, P, W and S. The Martin table text was read, but the SK length (1.125 in) is inconsistent with the other rows, SF's retailer length (2-1/16 in) differs from Martin's 2.000 in, and W / S screw entries are garbled, so those rows are not published here. Bore ranges and keyseat sizes per bushing were also not read legibly. Use Martin's, Dodge's or TB Wood's current catalogue for those sizes.\n- No files: the bushing's taper, flange and barrel profile are not in the tables read, so a bushing file would be invented. For hub design use the maker's CAD (links below).\n\nbushing  length L, in (mm)  bolt circle, in (mm)  cap screws (qty × size)  flange Ø, in (mm)\nSH  1.250 (31.8)  2.250 (57.1)  3 × 1/4-20 × 1-3/8  2.688 (68.3)\nSDS  1.375 (34.9)  2.688 (68.3)  3 × 1/4-20 × 1-3/8 (product page: 1-7/8)  3.188 (81.0)\nSD  1.813 (46.1)  2.688 (68.3)  3 × 1/4-20 × 1-7/8  3.188 (81.0)\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Martin Sprocket: Catalog E-1: QD bushings (page B-4): length L, bolt circle, cap screws for JA to S — web — Publisher's page; dimensions are facts — https://dcngli4g50fhp.cloudfront.net/userfiles/ad/martinsprocket/documents/martin_e_1_catalog.pdf\n- Applied Industrial: Martin SH 3/4 QD bushing: barrel 1.871, flange 2.688, bolt circle 2.25, 3 × 1/4-20 × 1-3/8 — web — Publisher's page; dimensions are facts — https://www.applied.com/c-brands/c-martin/sh-3-4/SH-Series-QD-Bushing-0-75-in-Bore/p/100001000\n- Applied Industrial: Martin SDS 1-5/8 QD bushing: flange 3.188, bolt circle 2.688, length through bore 1.375, 3 × 1/4 × 1-7/8 — web — Publisher's page; dimensions are facts — https://www.applied.com/c-martin-sds-1-5-8/p/100000978\n- Source Atlantic: Martin SD 1-3/16 QD bushing: barrel 2.187, flange 3.188, length 1.813, bolt circle 2.687, 1/4-20 × 1-7/8 — web — Publisher's page; dimensions are facts — https://www.sourceatlantic.ca/Product/SD-1-3-16\n- Martin Sprocket: Martin Sprocket & Gear CAD library (sprockets, QD and taper bushings) — web — Publisher's page; dimensions are facts — https://www.martinsprocket.com/\n\nNo true-size file yet: the published figures do not fix the whole shape; a measured scan is planned.\nAPI: https://xemstudio.com/api/geometry?object=qd-bushings-sh-sds-sd\n",
 "sources": [
  {
   "publisher": "Martin Sprocket",
   "title": "Catalog E-1: QD bushings (page B-4): length L, bolt circle, cap screws for JA to S",
   "url": "https://dcngli4g50fhp.cloudfront.net/userfiles/ad/martinsprocket/documents/martin_e_1_catalog.pdf",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Applied Industrial",
   "title": "Martin SH 3/4 QD bushing: barrel 1.871, flange 2.688, bolt circle 2.25, 3 × 1/4-20 × 1-3/8",
   "url": "https://www.applied.com/c-brands/c-martin/sh-3-4/SH-Series-QD-Bushing-0-75-in-Bore/p/100001000",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Applied Industrial",
   "title": "Martin SDS 1-5/8 QD bushing: flange 3.188, bolt circle 2.688, length through bore 1.375, 3 × 1/4 × 1-7/8",
   "url": "https://www.applied.com/c-martin-sds-1-5-8/p/100000978",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Source Atlantic",
   "title": "Martin SD 1-3/16 QD bushing: barrel 2.187, flange 3.188, length 1.813, bolt circle 2.687, 1/4-20 × 1-7/8",
   "url": "https://www.sourceatlantic.ca/Product/SD-1-3-16",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Martin Sprocket",
   "title": "Martin Sprocket & Gear CAD library (sprockets, QD and taper bushings)",
   "url": "https://www.martinsprocket.com/",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  }
 ],
 "xem": {
  "status": "not-scanned",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "taper-lock-bushings-1008-to-5050",
  "v-belt-pulley-grooves-iso-4183-narrow",
  "roller-chain-sprocket-dimensions-ansi",
  "parallel-keys-din-6885",
  "square-keys-inch",
  "metric-shafts"
 ],
 "fits": [],
 "dimensions": "exact (nominal, no tolerance added)",
 "dimension_rule": "All geometry on Xem Studio is exact (nominal, true size) with no tolerance added. 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. Typical accuracy by process and ISO 286 fits: https://xemstudio.com/tolerances/",
 "mating": [
  {
   "feature": "bolt circle",
   "exact": "SH 2.250 in; SDS and SD 2.688 in",
   "mates": "QD hub bolt circle of the same bushing letter (three cap screws)",
   "fit": "designed",
   "files": "all"
  },
  {
   "feature": "cap screws",
   "exact": "3 × 1/4-20 × 1-3/8 (SH), 1/4-20 × 1-7/8 (SD)",
   "mates": "hub tapped holes 1/4-20 (socket-head-cap-screws-inch)",
   "fit": "designed",
   "files": "all"
  }
 ],
 "fit_classes": {
  "press": "stays put: pin, tube, bearing or magnet held by interference. ISO 286 equivalent: H7/p6 (locational interference) or tighter.",
  "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. ISO 286 equivalent: H7/g6 or H7/h6.",
  "run": "turns or slides in use: pin in a link, rod through a guide. ISO 286 equivalent: H8/f7 (close running).",
  "socket": "large sliding fit: syringe barrel, sleeve, bobbin in a bore. ISO 286 equivalent: H9/d9 (free running) or looser.",
  "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 bolt circle does an SD QD bushing have?",
   "a": "2.688 in (68.3 mm): the same as the SDS; the flange diameter is 3.188 in and the length 1.813 in (SD) or 1.375 in (SDS)."
  },
  {
   "q": "What cap screws does an SH QD bushing use?",
   "a": "Three 1/4-20 × 1-3/8 in on a 2.250 in (57.2 mm) bolt circle; flange diameter 2.688 in."
  }
 ],
 "files_license": null,
 "offers": [],
 "markdown": "https://xemstudio.com/objects/qd-bushings-sh-sds-sd/index.md"
}