{
 "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": "roller-chain-sprocket-dimensions-ansi",
 "name": "Roller chain sprocket dimensions (ANSI): pitch diameter, outside diameter, caliper and tooth width, #25 to #80, 9 to 60 teeth",
 "kind": "standard",
 "category": "Hardware",
 "group": "Bearings, rails & motion",
 "year": null,
 "question": "What is the pitch diameter, outside diameter and tooth width of a #40 (or #25, #35, #50, #60, #80) roller chain sprocket with N teeth?",
 "tags": [
  "sprocket",
  "roller chain sprocket",
  "pitch diameter",
  "outside diameter",
  "caliper",
  "tooth width",
  "#40 sprocket",
  "#50 sprocket",
  "#60 sprocket",
  "#80 sprocket",
  "ansi b29.1",
  "standard",
  "tool"
 ],
 "aliases": [
  "40 chain sprocket pitch diameter",
  "#40 sprocket 20 tooth pitch diameter",
  "#50 sprocket dimensions",
  "#60 sprocket pitch diameter",
  "80 chain sprocket outside diameter",
  "sprocket pitch diameter formula",
  "sprocket outside diameter formula",
  "sprocket caliper diameter",
  "sprocket tooth width",
  "sprocket tooth width formula 0.93",
  "35 chain sprocket pd",
  "25 chain sprocket pd",
  "type a plate sprocket",
  "ansi sprocket tooth form",
  "sprocket seating curve radius",
  "roller chain sprocket calculator"
 ],
 "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/roller-chain-sprocket-dimensions-ansi/",
 "sheet_txt": "https://xemstudio.com/objects/roller-chain-sprocket-dimensions-ansi/sheet.txt",
 "sheet": {
  "basis": "ANSI sprocket formulas as printed by Martin Sprocket, Machinery's Handbook and Gizmology, tooth width checked against Martin's table; computed per tooth count; maker CAD linked",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "Formulas used for the table (all from the sources below; N = teeth, P = pitch, Dr = roller Ø): pitch Ø PD = P / sin(180° / N) (Martin, Gizmology); turned outside Ø OD = P × (0.6 + cot(180° / N)) (Martin, Machinery's Handbook, Gizmology); caliper Ø for an even tooth count = PD − Dr, for an odd count = PD × cos(90° / N) − Dr (Machinery's Handbook p. 1318; the page prints 'caliper factor = PD cos(90° ÷ N)'). Values are computed, not copied; PD of #40 with 20 teeth is 3.196 in (81.18 mm).",
   "OD is not critical to meshing (Martin): the table gives the turned OD above. Hob-cut and topped sprockets are a little different (OD = PD − Dr + 2 × the cutter's whole depth, Machinery's Handbook), and one forum tutorial uses OD = PD + P / 2; none of those figures are tabulated here, so check the maker's OD for a drawing. No source read gives a root-diameter formula, so none is tabulated; the caliper diameter is the practical check.",
   "Single-strand tooth width = 0.93 × inner width W − 0.006 in (Gizmology). It reproduces the first value of every row in Martin's single-strand tooth table for all six chains (#25 0.110, #35 0.168, #40 0.284, #50 0.343, #60 0.459, #80 0.575 in; #35 computes 0.169 against Martin's 0.168). Per-chain constants: #25: seat Ø Ds 0.1336 in (3.395 mm), seat radius R 0.0668 (1.697), working-curve radius E 0.1708 (4.339), ac 0.1040 (2.642), ab 0.1820 (4.623), single-strand tooth width 0.110 in (2.80 mm); #35: seat Ø Ds 0.2040 in (5.182 mm), seat radius R 0.1020 (2.591), working-curve radius E 0.2620 (6.655), ac 0.1600 (4.064), ab 0.2800 (7.112), single-strand tooth width 0.169 in (4.29 mm); #40: seat Ø Ds 0.3166 in (8.041 mm), seat radius R 0.1583 (4.020), working-curve radius E 0.4079 (10.360), ac 0.2496 (6.340), ab 0.4368 (11.095), single-strand tooth width 0.284 in (7.22 mm); #50: seat Ø Ds 0.4050 in (10.287 mm), seat radius R 0.2025 (5.143), working-curve radius E 0.5225 (13.271), ac 0.3200 (8.128), ab 0.5600 (14.224), single-strand tooth width 0.343 in (8.71 mm); #60: seat Ø Ds 0.4743 in (12.048 mm), seat radius R 0.2372 (6.024), working-curve radius E 0.6124 (15.554), ac 0.3752 (9.530), ab 0.6566 (16.678), single-strand tooth width 0.459 in (11.66 mm); #80: seat Ø Ds 0.6311 in (16.031 mm), seat radius R 0.3156 (8.015), working-curve radius E 0.8156 (20.715), ac 0.5000 (12.700), ab 0.8750 (22.225), single-strand tooth width 0.575 in (14.61 mm).",
   "ANSI B29.1 tooth-form constants read in the sources: seating-curve Ds = 1.005 Dr + 0.003 in (R = Ds / 2), working-curve radius E = 1.3025 Dr + 0.0015 in, G = 1.4 Dr (Machinery's Handbook p. 1330), seating angle A = 35° + 60° / N, B = 18° − 56° / N, ac = 0.8 Dr, ab = 1.4 Dr (Chief Delphi tutorial, which says the constants are from the ANSI standard). The remaining standard dimensions (chord yz, topping-curve radius F and offset H, S, W, V) could not be read from any source reachable here, so the full tooth outline is NOT drawn.",
   "No sprocket files: a tooth gap needs the whole ANSI outline, not just the seat arc, and the missing topping-curve numbers would have been invented. The existing roller-chain-sprockets page has #25 / #35 simplified-form files; its tooth form is labelled an approximation there. Martin says plate sprockets are normally made in sizes 7-1/2 in and larger, and type A (a plain plate with the tooth form and a bore) in all diameters; the plate thickness is the maker's choice.",
   "For a plate you intend to make yourself: use the PD, the seat Ø and the tooth width above, and cut the gaps with the maker's CAD (Tsubaki and Martin both offer it) or with the standard."
  ],
  "table": {
   "columns": [
    "chain",
    "teeth N",
    "pitch Ø PD, in",
    "pitch Ø PD, mm",
    "turned OD, in",
    "turned OD, mm",
    "caliper Ø, in",
    "caliper Ø, mm"
   ],
   "rows": [
    [
     "#25",
     "9",
     "0.731",
     "18.57",
     "0.837",
     "21.26",
     "0.590",
     "14.98"
    ],
    [
     "#25",
     "10",
     "0.809",
     "20.55",
     "0.919",
     "23.35",
     "0.679",
     "17.25"
    ],
    [
     "#25",
     "11",
     "0.887",
     "22.54",
     "1.001",
     "25.44",
     "0.748",
     "19.01"
    ],
    [
     "#25",
     "12",
     "0.966",
     "24.53",
     "1.083",
     "27.51",
     "0.836",
     "21.23"
    ],
    [
     "#25",
     "13",
     "1.045",
     "26.53",
     "1.164",
     "29.57",
     "0.907",
     "23.04"
    ],
    [
     "#25",
     "14",
     "1.123",
     "28.54",
     "1.245",
     "31.63",
     "0.993",
     "25.23"
    ],
    [
     "#25",
     "15",
     "1.202",
     "30.54",
     "1.326",
     "33.68",
     "1.066",
     "27.07"
    ],
    [
     "#25",
     "16",
     "1.281",
     "32.55",
     "1.407",
     "35.73",
     "1.151",
     "29.25"
    ],
    [
     "#25",
     "17",
     "1.361",
     "34.56",
     "1.487",
     "37.78",
     "1.225",
     "31.11"
    ],
    [
     "#25",
     "18",
     "1.440",
     "36.57",
     "1.568",
     "39.82",
     "1.310",
     "33.27"
    ],
    [
     "#25",
     "19",
     "1.519",
     "38.58",
     "1.648",
     "41.86",
     "1.384",
     "35.15"
    ],
    [
     "#25",
     "20",
     "1.598",
     "40.59",
     "1.728",
     "43.90",
     "1.468",
     "37.29"
    ],
    [
     "#25",
     "21",
     "1.677",
     "42.61",
     "1.809",
     "45.94",
     "1.543",
     "39.18"
    ],
    [
     "#25",
     "22",
     "1.757",
     "44.62",
     "1.889",
     "47.98",
     "1.627",
     "41.32"
    ],
    [
     "#25",
     "23",
     "1.836",
     "46.63",
     "1.969",
     "50.01",
     "1.702",
     "43.22"
    ],
    [
     "#25",
     "24",
     "1.915",
     "48.65",
     "2.049",
     "52.04",
     "1.785",
     "45.35"
    ],
    [
     "#25",
     "25",
     "1.995",
     "50.66",
     "2.129",
     "54.08",
     "1.861",
     "47.26"
    ],
    [
     "#25",
     "28",
     "2.233",
     "56.71",
     "2.369",
     "60.17",
     "2.103",
     "53.41"
    ],
    [
     "#25",
     "30",
     "2.392",
     "60.75",
     "2.529",
     "64.23",
     "2.262",
     "57.45"
    ],
    [
     "#25",
     "32",
     "2.551",
     "64.78",
     "2.688",
     "68.28",
     "2.421",
     "61.48"
    ],
    [
     "#25",
     "35",
     "2.789",
     "70.84",
     "2.928",
     "74.36",
     "2.656",
     "67.47"
    ],
    [
     "#25",
     "36",
     "2.868",
     "72.86",
     "3.008",
     "76.39",
     "2.738",
     "69.56"
    ],
    [
     "#25",
     "40",
     "3.186",
     "80.93",
     "3.327",
     "84.49",
     "3.056",
     "77.63"
    ],
    [
     "#25",
     "45",
     "3.584",
     "91.03",
     "3.725",
     "94.62",
     "3.452",
     "87.67"
    ],
    [
     "#25",
     "48",
     "3.822",
     "97.09",
     "3.964",
     "100.69",
     "3.692",
     "93.79"
    ],
    [
     "#25",
     "50",
     "3.981",
     "101.13",
     "4.124",
     "104.74",
     "3.851",
     "97.83"
    ],
    [
     "#25",
     "60",
     "4.777",
     "121.33",
     "4.920",
     "124.98",
     "4.647",
     "118.03"
    ],
    [
     "#35",
     "9",
     "1.096",
     "27.85",
     "1.255",
     "31.88",
     "0.880",
     "22.35"
    ],
    [
     "#35",
     "10",
     "1.214",
     "30.82",
     "1.379",
     "35.03",
     "1.014",
     "25.74"
    ],
    [
     "#35",
     "11",
     "1.331",
     "33.81",
     "1.502",
     "38.15",
     "1.118",
     "28.38"
    ],
    [
     "#35",
     "12",
     "1.449",
     "36.80",
     "1.625",
     "41.26",
     "1.249",
     "31.72"
    ],
    [
     "#35",
     "13",
     "1.567",
     "39.80",
     "1.746",
     "44.36",
     "1.356",
     "34.43"
    ],
    [
     "#35",
     "14",
     "1.685",
     "42.80",
     "1.868",
     "47.45",
     "1.485",
     "37.72"
    ],
    [
     "#35",
     "15",
     "1.804",
     "45.81",
     "1.989",
     "50.53",
     "1.594",
     "40.48"
    ],
    [
     "#35",
     "16",
     "1.922",
     "48.82",
     "2.110",
     "53.60",
     "1.722",
     "43.74"
    ],
    [
     "#35",
     "17",
     "2.041",
     "51.84",
     "2.231",
     "56.67",
     "1.832",
     "46.54"
    ],
    [
     "#35",
     "18",
     "2.160",
     "54.85",
     "2.352",
     "59.73",
     "1.960",
     "49.77"
    ],
    [
     "#35",
     "19",
     "2.278",
     "57.87",
     "2.472",
     "62.80",
     "2.071",
     "52.59"
    ],
    [
     "#35",
     "20",
     "2.397",
     "60.89",
     "2.593",
     "65.85",
     "2.197",
     "55.81"
    ],
    [
     "#35",
     "21",
     "2.516",
     "63.91",
     "2.713",
     "68.91",
     "2.309",
     "58.65"
    ],
    [
     "#35",
     "22",
     "2.635",
     "66.93",
     "2.833",
     "71.96",
     "2.435",
     "61.85"
    ],
    [
     "#35",
     "23",
     "2.754",
     "69.95",
     "2.953",
     "75.01",
     "2.548",
     "64.71"
    ],
    [
     "#35",
     "24",
     "2.873",
     "72.97",
     "3.073",
     "78.06",
     "2.673",
     "67.89"
    ],
    [
     "#35",
     "25",
     "2.992",
     "76.00",
     "3.193",
     "81.11",
     "2.786",
     "70.77"
    ],
    [
     "#35",
     "28",
     "3.349",
     "85.07",
     "3.553",
     "90.25",
     "3.149",
     "79.99"
    ],
    [
     "#35",
     "30",
     "3.588",
     "91.12",
     "3.793",
     "96.34",
     "3.388",
     "86.04"
    ],
    [
     "#35",
     "32",
     "3.826",
     "97.18",
     "4.032",
     "102.42",
     "3.626",
     "92.10"
    ],
    [
     "#35",
     "35",
     "4.183",
     "106.26",
     "4.392",
     "111.55",
     "3.979",
     "101.07"
    ],
    [
     "#35",
     "36",
     "4.303",
     "109.29",
     "4.511",
     "114.59",
     "4.103",
     "104.21"
    ],
    [
     "#35",
     "40",
     "4.780",
     "121.40",
     "4.990",
     "126.74",
     "4.580",
     "116.32"
    ],
    [
     "#35",
     "45",
     "5.376",
     "136.55",
     "5.588",
     "141.93",
     "5.173",
     "131.38"
    ],
    [
     "#35",
     "48",
     "5.734",
     "145.64",
     "5.946",
     "151.04",
     "5.534",
     "140.56"
    ],
    [
     "#35",
     "50",
     "5.972",
     "151.69",
     "6.185",
     "157.11",
     "5.772",
     "146.61"
    ],
    [
     "#35",
     "60",
     "7.165",
     "182.00",
     "7.380",
     "187.46",
     "6.965",
     "176.92"
    ],
    [
     "#40",
     "9",
     "1.462",
     "37.13",
     "1.674",
     "42.51",
     "1.128",
     "28.64"
    ],
    [
     "#40",
     "10",
     "1.618",
     "41.10",
     "1.839",
     "46.71",
     "1.306",
     "33.17"
    ],
    [
     "#40",
     "11",
     "1.775",
     "45.08",
     "2.003",
     "50.87",
     "1.445",
     "36.69"
    ],
    [
     "#40",
     "12",
     "1.932",
     "49.07",
     "2.166",
     "55.02",
     "1.620",
     "41.14"
    ],
    [
     "#40",
     "13",
     "2.089",
     "53.07",
     "2.329",
     "59.15",
     "1.762",
     "44.76"
    ],
    [
     "#40",
     "14",
     "2.247",
     "57.07",
     "2.491",
     "63.26",
     "1.935",
     "49.15"
    ],
    [
     "#40",
     "15",
     "2.405",
     "61.08",
     "2.652",
     "67.37",
     "2.080",
     "52.82"
    ],
    [
     "#40",
     "16",
     "2.563",
     "65.10",
     "2.814",
     "71.47",
     "2.251",
     "57.17"
    ],
    [
     "#40",
     "17",
     "2.721",
     "69.12",
     "2.975",
     "75.56",
     "2.397",
     "60.90"
    ],
    [
     "#40",
     "18",
     "2.879",
     "73.14",
     "3.136",
     "79.65",
     "2.567",
     "65.21"
    ],
    [
     "#40",
     "19",
     "3.038",
     "77.16",
     "3.296",
     "83.73",
     "2.715",
     "68.97"
    ],
    [
     "#40",
     "20",
     "3.196",
     "81.18",
     "3.457",
     "87.80",
     "2.884",
     "73.26"
    ],
    [
     "#40",
     "21",
     "3.355",
     "85.21",
     "3.617",
     "91.88",
     "3.033",
     "77.05"
    ],
    [
     "#40",
     "22",
     "3.513",
     "89.24",
     "3.778",
     "95.95",
     "3.201",
     "81.31"
    ],
    [
     "#40",
     "23",
     "3.672",
     "93.27",
     "3.938",
     "100.02",
     "3.351",
     "85.13"
    ],
    [
     "#40",
     "24",
     "3.831",
     "97.30",
     "4.098",
     "104.09",
     "3.519",
     "89.37"
    ],
    [
     "#40",
     "25",
     "3.989",
     "101.33",
     "4.258",
     "108.15",
     "3.669",
     "93.21"
    ],
    [
     "#40",
     "28",
     "4.466",
     "113.43",
     "4.738",
     "120.34",
     "4.154",
     "105.50"
    ],
    [
     "#40",
     "30",
     "4.783",
     "121.50",
     "5.057",
     "128.45",
     "4.471",
     "113.57"
    ],
    [
     "#40",
     "32",
     "5.101",
     "129.57",
     "5.377",
     "136.57",
     "4.789",
     "121.64"
    ],
    [
     "#40",
     "35",
     "5.578",
     "141.68",
     "5.855",
     "148.73",
     "5.260",
     "133.61"
    ],
    [
     "#40",
     "36",
     "5.737",
     "145.72",
     "6.015",
     "152.78",
     "5.425",
     "137.79"
    ],
    [
     "#40",
     "40",
     "6.373",
     "161.87",
     "6.653",
     "168.99",
     "6.061",
     "153.94"
    ],
    [
     "#40",
     "45",
     "7.168",
     "182.06",
     "7.450",
     "189.24",
     "6.851",
     "174.03"
    ],
    [
     "#40",
     "48",
     "7.645",
     "194.18",
     "7.929",
     "201.38",
     "7.333",
     "186.26"
    ],
    [
     "#40",
     "50",
     "7.963",
     "202.26",
     "8.247",
     "209.48",
     "7.651",
     "194.34"
    ],
    [
     "#40",
     "60",
     "9.554",
     "242.66",
     "9.841",
     "249.95",
     "9.242",
     "234.74"
    ],
    [
     "#50",
     "9",
     "1.827",
     "46.42",
     "2.092",
     "53.14",
     "1.400",
     "35.55"
    ],
    [
     "#50",
     "10",
     "2.023",
     "51.37",
     "2.299",
     "58.38",
     "1.623",
     "41.21"
    ],
    [
     "#50",
     "11",
     "2.218",
     "56.35",
     "2.504",
     "63.59",
     "1.796",
     "45.61"
    ],
    [
     "#50",
     "12",
     "2.415",
     "61.34",
     "2.708",
     "68.77",
     "2.015",
     "51.18"
    ],
    [
     "#50",
     "13",
     "2.612",
     "66.33",
     "2.911",
     "73.93",
     "2.193",
     "55.69"
    ],
    [
     "#50",
     "14",
     "2.809",
     "71.34",
     "3.113",
     "79.08",
     "2.409",
     "61.18"
    ],
    [
     "#50",
     "15",
     "3.006",
     "76.35",
     "3.315",
     "84.21",
     "2.590",
     "65.78"
    ],
    [
     "#50",
     "16",
     "3.204",
     "81.37",
     "3.517",
     "89.33",
     "2.804",
     "71.21"
    ],
    [
     "#50",
     "17",
     "3.401",
     "86.39",
     "3.718",
     "94.45",
     "2.987",
     "75.87"
    ],
    [
     "#50",
     "18",
     "3.599",
     "91.42",
     "3.920",
     "99.56",
     "3.199",
     "81.26"
    ],
    [
     "#50",
     "19",
     "3.797",
     "96.45",
     "4.120",
     "104.66",
     "3.384",
     "85.96"
    ],
    [
     "#50",
     "20",
     "3.995",
     "101.48",
     "4.321",
     "109.76",
     "3.595",
     "91.32"
    ],
    [
     "#50",
     "21",
     "4.193",
     "106.51",
     "4.522",
     "114.85",
     "3.782",
     "96.06"
    ],
    [
     "#50",
     "22",
     "4.392",
     "111.55",
     "4.722",
     "119.94",
     "3.992",
     "101.39"
    ],
    [
     "#50",
     "23",
     "4.590",
     "116.59",
     "4.922",
     "125.02",
     "4.179",
     "106.15"
    ],
    [
     "#50",
     "24",
     "4.788",
     "121.62",
     "5.122",
     "130.11",
     "4.388",
     "111.46"
    ],
    [
     "#50",
     "25",
     "4.987",
     "126.66",
     "5.322",
     "135.19",
     "4.577",
     "116.25"
    ],
    [
     "#50",
     "28",
     "5.582",
     "141.79",
     "5.922",
     "150.42",
     "5.182",
     "131.63"
    ],
    [
     "#50",
     "30",
     "5.979",
     "151.87",
     "6.321",
     "160.57",
     "5.579",
     "141.71"
    ],
    [
     "#50",
     "32",
     "6.376",
     "161.96",
     "6.721",
     "170.71",
     "5.976",
     "151.80"
    ],
    [
     "#50",
     "35",
     "6.972",
     "177.10",
     "7.319",
     "185.91",
     "6.565",
     "166.76"
    ],
    [
     "#50",
     "36",
     "7.171",
     "182.15",
     "7.519",
     "190.98",
     "6.771",
     "171.99"
    ],
    [
     "#50",
     "40",
     "7.966",
     "202.33",
     "8.316",
     "211.24",
     "7.566",
     "192.17"
    ],
    [
     "#50",
     "45",
     "8.960",
     "227.58",
     "9.313",
     "236.55",
     "8.554",
     "217.28"
    ],
    [
     "#50",
     "48",
     "9.556",
     "242.73",
     "9.911",
     "251.73",
     "9.156",
     "232.57"
    ],
    [
     "#50",
     "50",
     "9.954",
     "252.82",
     "10.309",
     "261.85",
     "9.554",
     "242.66"
    ],
    [
     "#50",
     "60",
     "11.942",
     "303.33",
     "12.301",
     "312.44",
     "11.542",
     "293.17"
    ],
    [
     "#60",
     "9",
     "2.193",
     "55.70",
     "2.511",
     "63.77",
     "1.691",
     "42.94"
    ],
    [
     "#60",
     "10",
     "2.427",
     "61.65",
     "2.758",
     "70.06",
     "1.958",
     "49.73"
    ],
    [
     "#60",
     "11",
     "2.662",
     "67.62",
     "3.004",
     "76.31",
     "2.166",
     "55.02"
    ],
    [
     "#60",
     "12",
     "2.898",
     "73.60",
     "3.249",
     "82.53",
     "2.429",
     "61.69"
    ],
    [
     "#60",
     "13",
     "3.134",
     "79.60",
     "3.493",
     "88.72",
     "2.642",
     "67.11"
    ],
    [
     "#60",
     "14",
     "3.370",
     "85.61",
     "3.736",
     "94.89",
     "2.901",
     "73.70"
    ],
    [
     "#60",
     "15",
     "3.607",
     "91.63",
     "3.978",
     "101.05",
     "3.119",
     "79.21"
    ],
    [
     "#60",
     "16",
     "3.844",
     "97.65",
     "4.221",
     "107.20",
     "3.375",
     "85.73"
    ],
    [
     "#60",
     "17",
     "4.082",
     "103.67",
     "4.462",
     "113.34",
     "3.595",
     "91.32"
    ],
    [
     "#60",
     "18",
     "4.319",
     "109.70",
     "4.703",
     "119.47",
     "3.850",
     "97.79"
    ],
    [
     "#60",
     "19",
     "4.557",
     "115.74",
     "4.945",
     "125.59",
     "4.072",
     "103.43"
    ],
    [
     "#60",
     "20",
     "4.794",
     "121.78",
     "5.185",
     "131.71",
     "4.325",
     "109.86"
    ],
    [
     "#60",
     "21",
     "5.032",
     "127.82",
     "5.426",
     "137.82",
     "4.549",
     "115.55"
    ],
    [
     "#60",
     "22",
     "5.270",
     "133.86",
     "5.666",
     "143.93",
     "4.801",
     "121.95"
    ],
    [
     "#60",
     "23",
     "5.508",
     "139.90",
     "5.907",
     "150.03",
     "5.026",
     "127.66"
    ],
    [
     "#60",
     "24",
     "5.746",
     "145.95",
     "6.147",
     "156.13",
     "5.277",
     "134.04"
    ],
    [
     "#60",
     "25",
     "5.984",
     "151.99",
     "6.387",
     "162.23",
     "5.503",
     "139.78"
    ],
    [
     "#60",
     "28",
     "6.699",
     "170.14",
     "7.106",
     "180.50",
     "6.230",
     "158.23"
    ],
    [
     "#60",
     "30",
     "7.175",
     "182.25",
     "7.586",
     "192.68",
     "6.706",
     "170.33"
    ],
    [
     "#60",
     "32",
     "7.652",
     "194.35",
     "8.065",
     "204.85",
     "7.183",
     "182.44"
    ],
    [
     "#60",
     "35",
     "8.367",
     "212.52",
     "8.783",
     "223.09",
     "7.889",
     "200.39"
    ],
    [
     "#60",
     "36",
     "8.605",
     "218.57",
     "9.023",
     "229.17",
     "8.136",
     "206.66"
    ],
    [
     "#60",
     "40",
     "9.559",
     "242.80",
     "9.980",
     "253.48",
     "9.090",
     "230.89"
    ],
    [
     "#60",
     "45",
     "10.752",
     "273.09",
     "11.175",
     "283.86",
     "10.276",
     "261.01"
    ],
    [
     "#60",
     "48",
     "11.467",
     "291.27",
     "11.893",
     "302.08",
     "10.998",
     "279.36"
    ],
    [
     "#60",
     "50",
     "11.944",
     "303.39",
     "12.371",
     "314.22",
     "11.475",
     "291.48"
    ],
    [
     "#60",
     "60",
     "14.330",
     "363.99",
     "14.761",
     "374.93",
     "13.861",
     "352.08"
    ],
    [
     "#80",
     "9",
     "2.924",
     "74.26",
     "3.347",
     "85.03",
     "2.254",
     "57.26"
    ],
    [
     "#80",
     "10",
     "3.236",
     "82.20",
     "3.678",
     "93.41",
     "2.611",
     "66.32"
    ],
    [
     "#80",
     "11",
     "3.549",
     "90.16",
     "4.006",
     "101.74",
     "2.888",
     "73.36"
    ],
    [
     "#80",
     "12",
     "3.864",
     "98.14",
     "4.332",
     "110.03",
     "3.239",
     "82.26"
    ],
    [
     "#80",
     "13",
     "4.179",
     "106.14",
     "4.657",
     "118.29",
     "3.523",
     "89.49"
    ],
    [
     "#80",
     "14",
     "4.494",
     "114.15",
     "4.981",
     "126.52",
     "3.869",
     "98.27"
    ],
    [
     "#80",
     "15",
     "4.810",
     "122.17",
     "5.305",
     "134.74",
     "4.158",
     "105.62"
    ],
    [
     "#80",
     "16",
     "5.126",
     "130.20",
     "5.627",
     "142.93",
     "4.501",
     "114.32"
    ],
    [
     "#80",
     "17",
     "5.442",
     "138.23",
     "5.950",
     "151.12",
     "4.794",
     "121.77"
    ],
    [
     "#80",
     "18",
     "5.759",
     "146.27",
     "6.271",
     "159.29",
     "5.134",
     "130.40"
    ],
    [
     "#80",
     "19",
     "6.076",
     "154.32",
     "6.593",
     "167.45",
     "5.430",
     "137.92"
    ],
    [
     "#80",
     "20",
     "6.392",
     "162.37",
     "6.914",
     "175.61",
     "5.767",
     "146.49"
    ],
    [
     "#80",
     "21",
     "6.710",
     "170.42",
     "7.235",
     "183.76",
     "6.066",
     "154.07"
    ],
    [
     "#80",
     "22",
     "7.027",
     "178.48",
     "7.555",
     "191.90",
     "6.402",
     "162.60"
    ],
    [
     "#80",
     "23",
     "7.344",
     "186.54",
     "7.876",
     "200.04",
     "6.702",
     "170.23"
    ],
    [
     "#80",
     "24",
     "7.661",
     "194.60",
     "8.196",
     "208.17",
     "7.036",
     "178.72"
    ],
    [
     "#80",
     "25",
     "7.979",
     "202.66",
     "8.516",
     "216.30",
     "7.338",
     "186.38"
    ],
    [
     "#80",
     "28",
     "8.931",
     "226.86",
     "9.475",
     "240.67",
     "8.306",
     "210.98"
    ],
    [
     "#80",
     "30",
     "9.567",
     "243.00",
     "10.114",
     "256.90",
     "8.942",
     "227.12"
    ],
    [
     "#80",
     "32",
     "10.202",
     "259.14",
     "10.753",
     "273.13",
     "9.577",
     "243.26"
    ],
    [
     "#80",
     "35",
     "11.156",
     "283.36",
     "11.711",
     "297.46",
     "10.520",
     "267.20"
    ],
    [
     "#80",
     "36",
     "11.474",
     "291.43",
     "12.030",
     "305.56",
     "10.849",
     "275.56"
    ],
    [
     "#80",
     "40",
     "12.745",
     "323.74",
     "13.306",
     "337.98",
     "12.120",
     "307.86"
    ],
    [
     "#80",
     "45",
     "14.336",
     "364.12",
     "14.901",
     "378.48",
     "13.702",
     "348.03"
    ],
    [
     "#80",
     "48",
     "15.290",
     "388.36",
     "15.857",
     "402.77",
     "14.665",
     "372.49"
    ],
    [
     "#80",
     "50",
     "15.926",
     "404.52",
     "16.495",
     "418.96",
     "15.301",
     "388.64"
    ],
    [
     "#80",
     "60",
     "19.107",
     "485.33",
     "19.681",
     "499.90",
     "18.482",
     "469.45"
    ]
   ]
  }
 },
 "sheet_text": "Roller chain sprocket dimensions (ANSI): pitch diameter, outside diameter, caliper and tooth width, #25 to #80, 9 to 60 teeth — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/roller-chain-sprocket-dimensions-ansi/  (sheet CC BY 4.0)\nBasis: ANSI sprocket formulas as printed by Martin Sprocket, Machinery's Handbook and Gizmology, tooth width checked against Martin's table; computed per tooth count; maker CAD linked\nCatalog version: 2026-10-20\n\nSizes: see table below\n- Formulas used for the table (all from the sources below; N = teeth, P = pitch, Dr = roller Ø): pitch Ø PD = P / sin(180° / N) (Martin, Gizmology); turned outside Ø OD = P × (0.6 + cot(180° / N)) (Martin, Machinery's Handbook, Gizmology); caliper Ø for an even tooth count = PD − Dr, for an odd count = PD × cos(90° / N) − Dr (Machinery's Handbook p. 1318; the page prints 'caliper factor = PD cos(90° ÷ N)'). Values are computed, not copied; PD of #40 with 20 teeth is 3.196 in (81.18 mm).\n- OD is not critical to meshing (Martin): the table gives the turned OD above. Hob-cut and topped sprockets are a little different (OD = PD − Dr + 2 × the cutter's whole depth, Machinery's Handbook), and one forum tutorial uses OD = PD + P / 2; none of those figures are tabulated here, so check the maker's OD for a drawing. No source read gives a root-diameter formula, so none is tabulated; the caliper diameter is the practical check.\n- Single-strand tooth width = 0.93 × inner width W − 0.006 in (Gizmology). It reproduces the first value of every row in Martin's single-strand tooth table for all six chains (#25 0.110, #35 0.168, #40 0.284, #50 0.343, #60 0.459, #80 0.575 in; #35 computes 0.169 against Martin's 0.168). Per-chain constants: #25: seat Ø Ds 0.1336 in (3.395 mm), seat radius R 0.0668 (1.697), working-curve radius E 0.1708 (4.339), ac 0.1040 (2.642), ab 0.1820 (4.623), single-strand tooth width 0.110 in (2.80 mm); #35: seat Ø Ds 0.2040 in (5.182 mm), seat radius R 0.1020 (2.591), working-curve radius E 0.2620 (6.655), ac 0.1600 (4.064), ab 0.2800 (7.112), single-strand tooth width 0.169 in (4.29 mm); #40: seat Ø Ds 0.3166 in (8.041 mm), seat radius R 0.1583 (4.020), working-curve radius E 0.4079 (10.360), ac 0.2496 (6.340), ab 0.4368 (11.095), single-strand tooth width 0.284 in (7.22 mm); #50: seat Ø Ds 0.4050 in (10.287 mm), seat radius R 0.2025 (5.143), working-curve radius E 0.5225 (13.271), ac 0.3200 (8.128), ab 0.5600 (14.224), single-strand tooth width 0.343 in (8.71 mm); #60: seat Ø Ds 0.4743 in (12.048 mm), seat radius R 0.2372 (6.024), working-curve radius E 0.6124 (15.554), ac 0.3752 (9.530), ab 0.6566 (16.678), single-strand tooth width 0.459 in (11.66 mm); #80: seat Ø Ds 0.6311 in (16.031 mm), seat radius R 0.3156 (8.015), working-curve radius E 0.8156 (20.715), ac 0.5000 (12.700), ab 0.8750 (22.225), single-strand tooth width 0.575 in (14.61 mm).\n- ANSI B29.1 tooth-form constants read in the sources: seating-curve Ds = 1.005 Dr + 0.003 in (R = Ds / 2), working-curve radius E = 1.3025 Dr + 0.0015 in, G = 1.4 Dr (Machinery's Handbook p. 1330), seating angle A = 35° + 60° / N, B = 18° − 56° / N, ac = 0.8 Dr, ab = 1.4 Dr (Chief Delphi tutorial, which says the constants are from the ANSI standard). The remaining standard dimensions (chord yz, topping-curve radius F and offset H, S, W, V) could not be read from any source reachable here, so the full tooth outline is NOT drawn.\n- No sprocket files: a tooth gap needs the whole ANSI outline, not just the seat arc, and the missing topping-curve numbers would have been invented. The existing roller-chain-sprockets page has #25 / #35 simplified-form files; its tooth form is labelled an approximation there. Martin says plate sprockets are normally made in sizes 7-1/2 in and larger, and type A (a plain plate with the tooth form and a bore) in all diameters; the plate thickness is the maker's choice.\n- For a plate you intend to make yourself: use the PD, the seat Ø and the tooth width above, and cut the gaps with the maker's CAD (Tsubaki and Martin both offer it) or with the standard.\n\nchain  teeth N  pitch Ø PD, in  pitch Ø PD, mm  turned OD, in  turned OD, mm  caliper Ø, in  caliper Ø, mm\n#25  9  0.731  18.57  0.837  21.26  0.590  14.98\n#25  10  0.809  20.55  0.919  23.35  0.679  17.25\n#25  11  0.887  22.54  1.001  25.44  0.748  19.01\n#25  12  0.966  24.53  1.083  27.51  0.836  21.23\n#25  13  1.045  26.53  1.164  29.57  0.907  23.04\n#25  14  1.123  28.54  1.245  31.63  0.993  25.23\n#25  15  1.202  30.54  1.326  33.68  1.066  27.07\n#25  16  1.281  32.55  1.407  35.73  1.151  29.25\n#25  17  1.361  34.56  1.487  37.78  1.225  31.11\n#25  18  1.440  36.57  1.568  39.82  1.310  33.27\n#25  19  1.519  38.58  1.648  41.86  1.384  35.15\n#25  20  1.598  40.59  1.728  43.90  1.468  37.29\n#25  21  1.677  42.61  1.809  45.94  1.543  39.18\n#25  22  1.757  44.62  1.889  47.98  1.627  41.32\n#25  23  1.836  46.63  1.969  50.01  1.702  43.22\n#25  24  1.915  48.65  2.049  52.04  1.785  45.35\n#25  25  1.995  50.66  2.129  54.08  1.861  47.26\n#25  28  2.233  56.71  2.369  60.17  2.103  53.41\n#25  30  2.392  60.75  2.529  64.23  2.262  57.45\n#25  32  2.551  64.78  2.688  68.28  2.421  61.48\n#25  35  2.789  70.84  2.928  74.36  2.656  67.47\n#25  36  2.868  72.86  3.008  76.39  2.738  69.56\n#25  40  3.186  80.93  3.327  84.49  3.056  77.63\n#25  45  3.584  91.03  3.725  94.62  3.452  87.67\n#25  48  3.822  97.09  3.964  100.69  3.692  93.79\n#25  50  3.981  101.13  4.124  104.74  3.851  97.83\n#25  60  4.777  121.33  4.920  124.98  4.647  118.03\n#35  9  1.096  27.85  1.255  31.88  0.880  22.35\n#35  10  1.214  30.82  1.379  35.03  1.014  25.74\n#35  11  1.331  33.81  1.502  38.15  1.118  28.38\n#35  12  1.449  36.80  1.625  41.26  1.249  31.72\n#35  13  1.567  39.80  1.746  44.36  1.356  34.43\n#35  14  1.685  42.80  1.868  47.45  1.485  37.72\n#35  15  1.804  45.81  1.989  50.53  1.594  40.48\n#35  16  1.922  48.82  2.110  53.60  1.722  43.74\n#35  17  2.041  51.84  2.231  56.67  1.832  46.54\n#35  18  2.160  54.85  2.352  59.73  1.960  49.77\n#35  19  2.278  57.87  2.472  62.80  2.071  52.59\n#35  20  2.397  60.89  2.593  65.85  2.197  55.81\n#35  21  2.516  63.91  2.713  68.91  2.309  58.65\n#35  22  2.635  66.93  2.833  71.96  2.435  61.85\n#35  23  2.754  69.95  2.953  75.01  2.548  64.71\n#35  24  2.873  72.97  3.073  78.06  2.673  67.89\n#35  25  2.992  76.00  3.193  81.11  2.786  70.77\n#35  28  3.349  85.07  3.553  90.25  3.149  79.99\n#35  30  3.588  91.12  3.793  96.34  3.388  86.04\n#35  32  3.826  97.18  4.032  102.42  3.626  92.10\n#35  35  4.183  106.26  4.392  111.55  3.979  101.07\n#35  36  4.303  109.29  4.511  114.59  4.103  104.21\n#35  40  4.780  121.40  4.990  126.74  4.580  116.32\n#35  45  5.376  136.55  5.588  141.93  5.173  131.38\n#35  48  5.734  145.64  5.946  151.04  5.534  140.56\n#35  50  5.972  151.69  6.185  157.11  5.772  146.61\n#35  60  7.165  182.00  7.380  187.46  6.965  176.92\n#40  9  1.462  37.13  1.674  42.51  1.128  28.64\n#40  10  1.618  41.10  1.839  46.71  1.306  33.17\n#40  11  1.775  45.08  2.003  50.87  1.445  36.69\n#40  12  1.932  49.07  2.166  55.02  1.620  41.14\n#40  13  2.089  53.07  2.329  59.15  1.762  44.76\n#40  14  2.247  57.07  2.491  63.26  1.935  49.15\n#40  15  2.405  61.08  2.652  67.37  2.080  52.82\n#40  16  2.563  65.10  2.814  71.47  2.251  57.17\n#40  17  2.721  69.12  2.975  75.56  2.397  60.90\n#40  18  2.879  73.14  3.136  79.65  2.567  65.21\n#40  19  3.038  77.16  3.296  83.73  2.715  68.97\n#40  20  3.196  81.18  3.457  87.80  2.884  73.26\n#40  21  3.355  85.21  3.617  91.88  3.033  77.05\n#40  22  3.513  89.24  3.778  95.95  3.201  81.31\n#40  23  3.672  93.27  3.938  100.02  3.351  85.13\n#40  24  3.831  97.30  4.098  104.09  3.519  89.37\n#40  25  3.989  101.33  4.258  108.15  3.669  93.21\n#40  28  4.466  113.43  4.738  120.34  4.154  105.50\n#40  30  4.783  121.50  5.057  128.45  4.471  113.57\n#40  32  5.101  129.57  5.377  136.57  4.789  121.64\n#40  35  5.578  141.68  5.855  148.73  5.260  133.61\n#40  36  5.737  145.72  6.015  152.78  5.425  137.79\n#40  40  6.373  161.87  6.653  168.99  6.061  153.94\n#40  45  7.168  182.06  7.450  189.24  6.851  174.03\n#40  48  7.645  194.18  7.929  201.38  7.333  186.26\n#40  50  7.963  202.26  8.247  209.48  7.651  194.34\n#40  60  9.554  242.66  9.841  249.95  9.242  234.74\n#50  9  1.827  46.42  2.092  53.14  1.400  35.55\n#50  10  2.023  51.37  2.299  58.38  1.623  41.21\n#50  11  2.218  56.35  2.504  63.59  1.796  45.61\n#50  12  2.415  61.34  2.708  68.77  2.015  51.18\n#50  13  2.612  66.33  2.911  73.93  2.193  55.69\n#50  14  2.809  71.34  3.113  79.08  2.409  61.18\n#50  15  3.006  76.35  3.315  84.21  2.590  65.78\n#50  16  3.204  81.37  3.517  89.33  2.804  71.21\n#50  17  3.401  86.39  3.718  94.45  2.987  75.87\n#50  18  3.599  91.42  3.920  99.56  3.199  81.26\n#50  19  3.797  96.45  4.120  104.66  3.384  85.96\n#50  20  3.995  101.48  4.321  109.76  3.595  91.32\n#50  21  4.193  106.51  4.522  114.85  3.782  96.06\n#50  22  4.392  111.55  4.722  119.94  3.992  101.39\n#50  23  4.590  116.59  4.922  125.02  4.179  106.15\n#50  24  4.788  121.62  5.122  130.11  4.388  111.46\n#50  25  4.987  126.66  5.322  135.19  4.577  116.25\n#50  28  5.582  141.79  5.922  150.42  5.182  131.63\n#50  30  5.979  151.87  6.321  160.57  5.579  141.71\n#50  32  6.376  161.96  6.721  170.71  5.976  151.80\n#50  35  6.972  177.10  7.319  185.91  6.565  166.76\n#50  36  7.171  182.15  7.519  190.98  6.771  171.99\n#50  40  7.966  202.33  8.316  211.24  7.566  192.17\n#50  45  8.960  227.58  9.313  236.55  8.554  217.28\n#50  48  9.556  242.73  9.911  251.73  9.156  232.57\n#50  50  9.954  252.82  10.309  261.85  9.554  242.66\n#50  60  11.942  303.33  12.301  312.44  11.542  293.17\n#60  9  2.193  55.70  2.511  63.77  1.691  42.94\n#60  10  2.427  61.65  2.758  70.06  1.958  49.73\n#60  11  2.662  67.62  3.004  76.31  2.166  55.02\n#60  12  2.898  73.60  3.249  82.53  2.429  61.69\n#60  13  3.134  79.60  3.493  88.72  2.642  67.11\n#60  14  3.370  85.61  3.736  94.89  2.901  73.70\n#60  15  3.607  91.63  3.978  101.05  3.119  79.21\n#60  16  3.844  97.65  4.221  107.20  3.375  85.73\n#60  17  4.082  103.67  4.462  113.34  3.595  91.32\n#60  18  4.319  109.70  4.703  119.47  3.850  97.79\n#60  19  4.557  115.74  4.945  125.59  4.072  103.43\n#60  20  4.794  121.78  5.185  131.71  4.325  109.86\n#60  21  5.032  127.82  5.426  137.82  4.549  115.55\n#60  22  5.270  133.86  5.666  143.93  4.801  121.95\n#60  23  5.508  139.90  5.907  150.03  5.026  127.66\n#60  24  5.746  145.95  6.147  156.13  5.277  134.04\n#60  25  5.984  151.99  6.387  162.23  5.503  139.78\n#60  28  6.699  170.14  7.106  180.50  6.230  158.23\n#60  30  7.175  182.25  7.586  192.68  6.706  170.33\n#60  32  7.652  194.35  8.065  204.85  7.183  182.44\n#60  35  8.367  212.52  8.783  223.09  7.889  200.39\n#60  36  8.605  218.57  9.023  229.17  8.136  206.66\n#60  40  9.559  242.80  9.980  253.48  9.090  230.89\n#60  45  10.752  273.09  11.175  283.86  10.276  261.01\n#60  48  11.467  291.27  11.893  302.08  10.998  279.36\n#60  50  11.944  303.39  12.371  314.22  11.475  291.48\n#60  60  14.330  363.99  14.761  374.93  13.861  352.08\n#80  9  2.924  74.26  3.347  85.03  2.254  57.26\n#80  10  3.236  82.20  3.678  93.41  2.611  66.32\n#80  11  3.549  90.16  4.006  101.74  2.888  73.36\n#80  12  3.864  98.14  4.332  110.03  3.239  82.26\n#80  13  4.179  106.14  4.657  118.29  3.523  89.49\n#80  14  4.494  114.15  4.981  126.52  3.869  98.27\n#80  15  4.810  122.17  5.305  134.74  4.158  105.62\n#80  16  5.126  130.20  5.627  142.93  4.501  114.32\n#80  17  5.442  138.23  5.950  151.12  4.794  121.77\n#80  18  5.759  146.27  6.271  159.29  5.134  130.40\n#80  19  6.076  154.32  6.593  167.45  5.430  137.92\n#80  20  6.392  162.37  6.914  175.61  5.767  146.49\n#80  21  6.710  170.42  7.235  183.76  6.066  154.07\n#80  22  7.027  178.48  7.555  191.90  6.402  162.60\n#80  23  7.344  186.54  7.876  200.04  6.702  170.23\n#80  24  7.661  194.60  8.196  208.17  7.036  178.72\n#80  25  7.979  202.66  8.516  216.30  7.338  186.38\n#80  28  8.931  226.86  9.475  240.67  8.306  210.98\n#80  30  9.567  243.00  10.114  256.90  8.942  227.12\n#80  32  10.202  259.14  10.753  273.13  9.577  243.26\n#80  35  11.156  283.36  11.711  297.46  10.520  267.20\n#80  36  11.474  291.43  12.030  305.56  10.849  275.56\n#80  40  12.745  323.74  13.306  337.98  12.120  307.86\n#80  45  14.336  364.12  14.901  378.48  13.702  348.03\n#80  48  15.290  388.36  15.857  402.77  14.665  372.49\n#80  50  15.926  404.52  16.495  418.96  15.301  388.64\n#80  60  19.107  485.33  19.681  499.90  18.482  469.45\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Martin Sprocket: Sprocket engineering data: PD = pitch / sin(180 / N), OD = pitch (0.6 + cot(180 / N)), roller width and diameter, single-strand tooth width table — web — Publisher's page; dimensions are facts — https://www.martinsprocket.com/docs/catalogs/engineering/engineering%20catalog/sprocket-engineering-data.pdf\n- Machinery's Handbook, 31st ed.: Transmission roller chains: caliper diameter (PD cos(90 / N) − Dr for odd teeth), turned OD formula, working curve E = 1.3025 Dr + 0.0015 in, G = 1.4 Dr — web — Publisher's page; dimensions are facts — https://online.flippingbook.com/view/954046886/1318\n- Machinery's Handbook, 31st ed.: Transmission roller chains, hob layout page: E and G for all ranges — web — Publisher's page; dimensions are facts — https://online.flippingbook.com/view/954046886/1330\n- Chief Delphi (forum tutorial): Sprocket design tutorial: ANSI constants A = 35° + 60° / n, B = 18° − 56° / n, R = Ds / 2, Ds = 1.005 Dr + 0.003 in, ac = 0.8 Dr, ab = 1.4 Dr — web — Publisher's page; dimensions are facts — https://www.chiefdelphi.com/t/sprocket-design-tutorial/387449\n- Gizmology (notes quoted on meslab.org): Notes on sprockets and chains: PD, OD and sprocket thickness = 0.93 × roller width − 0.006 in — web — Publisher's page; dimensions are facts — https://meslab.org/goto/post?id=71581\n- ASME: ASME B29.1-2011 Precision power transmission roller chains, attachments, and sprockets (the standard itself, paid) — web — Publisher's page; dimensions are facts — https://webstore.ansi.org/standards/asme/asmeb292011r2022\n- Tsubaki (US): Roller chain, sprockets and TAPER-LOCK bushings: maker catalogue with CAD downloads — web — Publisher's page; dimensions are facts — https://www.tsubaki.com/\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=roller-chain-sprocket-dimensions-ansi\n",
 "sources": [
  {
   "publisher": "Martin Sprocket",
   "title": "Sprocket engineering data: PD = pitch / sin(180 / N), OD = pitch (0.6 + cot(180 / N)), roller width and diameter, single-strand tooth width table",
   "url": "https://www.martinsprocket.com/docs/catalogs/engineering/engineering%20catalog/sprocket-engineering-data.pdf",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Machinery's Handbook, 31st ed.",
   "title": "Transmission roller chains: caliper diameter (PD cos(90 / N) − Dr for odd teeth), turned OD formula, working curve E = 1.3025 Dr + 0.0015 in, G = 1.4 Dr",
   "url": "https://online.flippingbook.com/view/954046886/1318",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Machinery's Handbook, 31st ed.",
   "title": "Transmission roller chains, hob layout page: E and G for all ranges",
   "url": "https://online.flippingbook.com/view/954046886/1330",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Chief Delphi (forum tutorial)",
   "title": "Sprocket design tutorial: ANSI constants A = 35° + 60° / n, B = 18° − 56° / n, R = Ds / 2, Ds = 1.005 Dr + 0.003 in, ac = 0.8 Dr, ab = 1.4 Dr",
   "url": "https://www.chiefdelphi.com/t/sprocket-design-tutorial/387449",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Gizmology (notes quoted on meslab.org)",
   "title": "Notes on sprockets and chains: PD, OD and sprocket thickness = 0.93 × roller width − 0.006 in",
   "url": "https://meslab.org/goto/post?id=71581",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "ASME",
   "title": "ASME B29.1-2011 Precision power transmission roller chains, attachments, and sprockets (the standard itself, paid)",
   "url": "https://webstore.ansi.org/standards/asme/asmeb292011r2022",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Tsubaki (US)",
   "title": "Roller chain, sprockets and TAPER-LOCK bushings: maker catalogue with CAD downloads",
   "url": "https://www.tsubaki.com/",
   "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": [
  "roller-chain-sprockets",
  "roller-chain-ansi-b29-1-25-to-80",
  "taper-lock-bushings-1008-to-5050",
  "qd-bushings-sh-sds-sd",
  "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": "roller seat Ø",
   "exact": "Ds = 1.005 Dr + 0.003 in (#40: 0.316 in)",
   "mates": "chain roller of Ø Dr (roller-chain-ansi-b29-1-25-to-80)",
   "fit": "run",
   "files": "all"
  },
  {
   "feature": "tooth width",
   "exact": "0.93 W − 0.006 in single strand (#40: 0.284 in)",
   "mates": "chain inner width W between inner plates",
   "fit": "run",
   "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 is the pitch diameter of a 20 tooth #40 sprocket?",
   "a": "3.196 in (81.18 mm): PD = 0.5 in / sin(9°). Its turned OD is 3.457 in (87.8 mm)."
  },
  {
   "q": "What is the tooth width of a #40 sprocket?",
   "a": "0.284 in (7.2 mm) for a single strand: 0.93 × 0.312 in − 0.006 in, the same as Martin's table."
  },
  {
   "q": "How do I measure an odd-tooth sprocket?",
   "a": "Over the nearly opposite tooth spaces: caliper Ø = PD × cos(90° / N) − roller Ø; for even tooth counts it is PD − roller Ø."
  },
  {
   "q": "Is the sprocket seat radius the same as the roller radius?",
   "a": "No: the seat diameter is 1.005 × roller Ø + 0.003 in, so the roller sits in a seat a few thousandths larger."
  }
 ],
 "files_license": null,
 "offers": [],
 "markdown": "https://xemstudio.com/objects/roller-chain-sprocket-dimensions-ansi/index.md"
}