{
 "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-ansi-b29-1-25-to-80",
 "name": "Roller chain ANSI B29.1 #25, #35, #40, #50, #60, #80: pitch, roller diameter, inner width, pin, plate height",
 "kind": "standard",
 "category": "Hardware",
 "group": "Bearings, rails & motion",
 "year": null,
 "question": "What are the dimensions of ANSI #40 (or #25, #35, #50, #60, #80) roller chain: pitch, roller diameter, inner width, pin diameter, plate thickness and plate height?",
 "tags": [
  "roller chain",
  "ansi chain",
  "#40 chain",
  "#50 chain",
  "#60 chain",
  "#80 chain",
  "#35 chain",
  "#25 chain",
  "pitch",
  "chain size",
  "standard",
  "tool"
 ],
 "aliases": [
  "#40 roller chain dimensions",
  "#50 roller chain dimensions",
  "#60 chain",
  "#80 chain",
  "#35 chain dimensions",
  "#25 chain dimensions",
  "ansi 40 chain pitch",
  "ansi 50 chain pitch",
  "roller chain size chart",
  "chain roller diameter",
  "roller chain inner width",
  "roller chain plate height",
  "asme b29.1 chain",
  "40 chain pin diameter",
  "40 chain pitch 1/2 in",
  "roller chain pitch chart",
  "ansi roller chain 80 pitch 1 inch"
 ],
 "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-ansi-b29-1-25-to-80/",
 "sheet_txt": "https://xemstudio.com/objects/roller-chain-ansi-b29-1-25-to-80/sheet.txt",
 "sheet": {
  "basis": "ASME B29.1M roller chain table as published by Engineers Edge, cross-checked against Martin Sprocket, A-Metric and Peer Chain; disagreements are shown; maker CAD linked",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "ANSI (ASME B29.1) roller chain numbers follow the pitch in this table: the digits before the final 0 are the pitch in eighths of an inch (#40 = 4/8 = 1/2 in, #50 = 5/8, #60 = 6/8 = 3/4 in, #80 = 8/8 = 1 in; #25 = 2/8 and #35 = 3/8 in). Engineers Edge marks #25 and #35 as bushing chain without rollers: their 'roller' Ø in the table is the bushing Ø.",
   "Agreement: pitch, roller Ø, inner width, pin Ø and plate thickness for all six sizes come from Engineers Edge's ASME B29.1M table. Martin Sprocket prints the same roller width and roller Ø for all six; A-Metric agrees to rounding (roller Ø within 0.002 in, pin Ø within 0.001 in, plate thickness within 0.0035 in, #40's 0.313 vs 0.312). Roller Ø and inner width are maxima / nominal catalogue values; the standard's tolerances are not tabulated here.",
   "Disagreements, shown rather than averaged: plate height. Engineers Edge gives the standard's maximum roller-link plate height as 0.95 P (0.238, 0.356, 0.475, 0.594, 0.713, 0.950 in; pin-link plates are lower at 0.82 P); A-Metric prints the plate depth h2 slightly lower (0.236, 0.354, 0.472, 0.594, 0.709, 0.945) and Peer Chain prints 0.228 for #25 and 0.712 for #60. Plate height is a maximum, so 0.95 P is the limit to design a guard or a housing around; real plates vary by maker. A-Metric's inside widths (0.309, 0.370, 0.495, 0.620 for #40, 50, 60, 80) are slightly under the 0.312 / 0.375 / 0.500 / 0.625 of the other tables.",
   "Peer Chain's size chart disagrees in two places and is not used for those values: #80 pitch printed as 1.25 in (the other four sources, and the chain number itself, say 1.000 in) and #50 roller Ø / width printed as 0.375 / 0.400 (Engineers Edge, Martin and A-Metric: roller Ø 0.400, width 0.375, so those two columns look swapped there). Its #60 pitch prints 0.751.",
   "Widths: 'roller link width max' is Engineers Edge's W + 2.12 × plate thickness (the outer width of an inner link). 'Overall width' is A-Metric's chain width over pin ends; connecting links are wider. Measuring load is the chain length-measuring load in ASME B29.1M as printed by Engineers Edge (lbf).",
   "No files: the link plate is a peanut shape whose waist depth and end radii are in the standard's drawing, not in the tables read, so a chain model would be invented. Sprocket dimensions for these chains are on the companion page; the existing roller-chain-sprockets page has simplified #25 and #35 sprocket files.",
   "Chain CAD: Tsubaki and Martin publish CAD for their own chain and sprockets (linked below); the standard itself is ASME B29.1-2011 (paid)."
  ],
  "table": {
   "columns": [
    "ANSI chain no.",
    "pitch P, in (mm)",
    "roller Ø Dr max, in (mm)",
    "inner width W, in (mm)",
    "pin Ø, in (mm)",
    "plate thickness, in (mm)",
    "plate height max (0.95 P), in (mm)",
    "plate height, A-Metric h2, in",
    "plate height, Peer H, in",
    "roller link width max, in (mm)",
    "overall width, A-Metric, in",
    "measuring load, lbf"
   ],
   "rows": [
    [
     "#25",
     "0.250 (6.35)",
     "0.130 (3.30)",
     "0.125 (3.17)",
     "0.0905 (2.30)",
     "0.030 (0.76)",
     "0.238 (6.05)",
     "0.236",
     "0.228",
     "0.189 (4.80)",
     "0.311",
     "18"
    ],
    [
     "#35",
     "0.375 (9.52)",
     "0.200 (5.08)",
     "0.188 (4.78)",
     "0.1410 (3.58)",
     "0.050 (1.27)",
     "0.356 (9.04)",
     "0.354",
     "0.356",
     "0.294 (7.47)",
     "0.488",
     "18"
    ],
    [
     "#40",
     "0.500 (12.70)",
     "0.312 (7.92)",
     "0.312 (7.92)",
     "0.1560 (3.96)",
     "0.060 (1.52)",
     "0.475 (12.06)",
     "0.472",
     "0.475",
     "0.439 (11.15)",
     "0.654",
     "31"
    ],
    [
     "#50",
     "0.625 (15.88)",
     "0.400 (10.16)",
     "0.375 (9.52)",
     "0.2000 (5.08)",
     "0.080 (2.03)",
     "0.594 (15.09)",
     "0.594",
     "0.594",
     "0.545 (13.84)",
     "0.815",
     "49"
    ],
    [
     "#60",
     "0.750 (19.05)",
     "0.469 (11.91)",
     "0.500 (12.70)",
     "0.2340 (5.94)",
     "0.094 (2.39)",
     "0.713 (18.11)",
     "0.709",
     "0.712",
     "0.699 (17.75)",
     "1.020",
     "70"
    ],
    [
     "#80",
     "1.000 (25.40)",
     "0.625 (15.88)",
     "0.625 (15.88)",
     "0.3120 (7.92)",
     "0.125 (3.17)",
     "0.950 (24.13)",
     "0.945",
     "0.950",
     "0.890 (22.61)",
     "1.287",
     "125"
    ]
   ]
  }
 },
 "sheet_text": "Roller chain ANSI B29.1 #25, #35, #40, #50, #60, #80: pitch, roller diameter, inner width, pin, plate height — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/roller-chain-ansi-b29-1-25-to-80/  (sheet CC BY 4.0)\nBasis: ASME B29.1M roller chain table as published by Engineers Edge, cross-checked against Martin Sprocket, A-Metric and Peer Chain; disagreements are shown; maker CAD linked\nCatalog version: 2026-10-20\n\nSizes: see table below\n- ANSI (ASME B29.1) roller chain numbers follow the pitch in this table: the digits before the final 0 are the pitch in eighths of an inch (#40 = 4/8 = 1/2 in, #50 = 5/8, #60 = 6/8 = 3/4 in, #80 = 8/8 = 1 in; #25 = 2/8 and #35 = 3/8 in). Engineers Edge marks #25 and #35 as bushing chain without rollers: their 'roller' Ø in the table is the bushing Ø.\n- Agreement: pitch, roller Ø, inner width, pin Ø and plate thickness for all six sizes come from Engineers Edge's ASME B29.1M table. Martin Sprocket prints the same roller width and roller Ø for all six; A-Metric agrees to rounding (roller Ø within 0.002 in, pin Ø within 0.001 in, plate thickness within 0.0035 in, #40's 0.313 vs 0.312). Roller Ø and inner width are maxima / nominal catalogue values; the standard's tolerances are not tabulated here.\n- Disagreements, shown rather than averaged: plate height. Engineers Edge gives the standard's maximum roller-link plate height as 0.95 P (0.238, 0.356, 0.475, 0.594, 0.713, 0.950 in; pin-link plates are lower at 0.82 P); A-Metric prints the plate depth h2 slightly lower (0.236, 0.354, 0.472, 0.594, 0.709, 0.945) and Peer Chain prints 0.228 for #25 and 0.712 for #60. Plate height is a maximum, so 0.95 P is the limit to design a guard or a housing around; real plates vary by maker. A-Metric's inside widths (0.309, 0.370, 0.495, 0.620 for #40, 50, 60, 80) are slightly under the 0.312 / 0.375 / 0.500 / 0.625 of the other tables.\n- Peer Chain's size chart disagrees in two places and is not used for those values: #80 pitch printed as 1.25 in (the other four sources, and the chain number itself, say 1.000 in) and #50 roller Ø / width printed as 0.375 / 0.400 (Engineers Edge, Martin and A-Metric: roller Ø 0.400, width 0.375, so those two columns look swapped there). Its #60 pitch prints 0.751.\n- Widths: 'roller link width max' is Engineers Edge's W + 2.12 × plate thickness (the outer width of an inner link). 'Overall width' is A-Metric's chain width over pin ends; connecting links are wider. Measuring load is the chain length-measuring load in ASME B29.1M as printed by Engineers Edge (lbf).\n- No files: the link plate is a peanut shape whose waist depth and end radii are in the standard's drawing, not in the tables read, so a chain model would be invented. Sprocket dimensions for these chains are on the companion page; the existing roller-chain-sprockets page has simplified #25 and #35 sprocket files.\n- Chain CAD: Tsubaki and Martin publish CAD for their own chain and sprockets (linked below); the standard itself is ASME B29.1-2011 (paid).\n\nANSI chain no.  pitch P, in (mm)  roller Ø Dr max, in (mm)  inner width W, in (mm)  pin Ø, in (mm)  plate thickness, in (mm)  plate height max (0.95 P), in (mm)  plate height, A-Metric h2, in  plate height, Peer H, in  roller link width max, in (mm)  overall width, A-Metric, in  measuring load, lbf\n#25  0.250 (6.35)  0.130 (3.30)  0.125 (3.17)  0.0905 (2.30)  0.030 (0.76)  0.238 (6.05)  0.236  0.228  0.189 (4.80)  0.311  18\n#35  0.375 (9.52)  0.200 (5.08)  0.188 (4.78)  0.1410 (3.58)  0.050 (1.27)  0.356 (9.04)  0.354  0.356  0.294 (7.47)  0.488  18\n#40  0.500 (12.70)  0.312 (7.92)  0.312 (7.92)  0.1560 (3.96)  0.060 (1.52)  0.475 (12.06)  0.472  0.475  0.439 (11.15)  0.654  31\n#50  0.625 (15.88)  0.400 (10.16)  0.375 (9.52)  0.2000 (5.08)  0.080 (2.03)  0.594 (15.09)  0.594  0.594  0.545 (13.84)  0.815  49\n#60  0.750 (19.05)  0.469 (11.91)  0.500 (12.70)  0.2340 (5.94)  0.094 (2.39)  0.713 (18.11)  0.709  0.712  0.699 (17.75)  1.020  70\n#80  1.000 (25.40)  0.625 (15.88)  0.625 (15.88)  0.3120 (7.92)  0.125 (3.17)  0.950 (24.13)  0.945  0.950  0.890 (22.61)  1.287  125\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Engineers Edge: Roller chain dimensions per ASME/ANSI B29.1M: pitch, max roller Ø, width, pin Ø, plate thickness, plate height formulas (0.95 P roller link, 0.82 P pin link) — web — Publisher's page; dimensions are facts — https://engineersedge.com/power_transmission/roller_chain_dimensions_13610.htm\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- A-Metric: ANSI roller chain: pitch, roller Ø, inside width, pin Ø, plate thickness, plate depth h2, overall width — web — Publisher's page; dimensions are facts — https://www.ametric.com/images/document/Chain-RollerANSI.pdf\n- Peer Chain: Single strand roller chain size chart: pitch, roller Ø, width, pin Ø, plate thickness, plate height — web — Publisher's page; dimensions are facts — https://www.peerchain.com/wp-content/uploads/2024/09/Single-Strand-Roller-Chain-Size-Chart.pdf\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-ansi-b29-1-25-to-80\n",
 "sources": [
  {
   "publisher": "Engineers Edge",
   "title": "Roller chain dimensions per ASME/ANSI B29.1M: pitch, max roller Ø, width, pin Ø, plate thickness, plate height formulas (0.95 P roller link, 0.82 P pin link)",
   "url": "https://engineersedge.com/power_transmission/roller_chain_dimensions_13610.htm",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "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": "A-Metric",
   "title": "ANSI roller chain: pitch, roller Ø, inside width, pin Ø, plate thickness, plate depth h2, overall width",
   "url": "https://www.ametric.com/images/document/Chain-RollerANSI.pdf",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Peer Chain",
   "title": "Single strand roller chain size chart: pitch, roller Ø, width, pin Ø, plate thickness, plate height",
   "url": "https://www.peerchain.com/wp-content/uploads/2024/09/Single-Strand-Roller-Chain-Size-Chart.pdf",
   "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-sprocket-dimensions-ansi",
  "metric-shafts",
  "taper-lock-bushings-1008-to-5050",
  "qd-bushings-sh-sds-sd",
  "timing-belt-profiles-pitch-and-tooth"
 ],
 "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": "inner width / roller Ø",
   "exact": "W and Dr per chain no. (#40: 0.312 / 0.312 in)",
   "mates": "sprocket tooth width 0.93 W − 0.006 and seat Ø 1.005 Dr + 0.003 (roller-chain-sprocket-dimensions-ansi, roller-chain-sprockets)",
   "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 of #40 roller chain?",
   "a": "1/2 in (12.70 mm): roller Ø 0.312 in (7.92 mm), inner width 0.312 in (7.92 mm), pin Ø 0.156 in (3.96 mm), plate thickness 0.060 in (1.52 mm)."
  },
  {
   "q": "What is the pitch of #50, #60 and #80 chain?",
   "a": "#50 is 5/8 in (15.875 mm), #60 is 3/4 in (19.05 mm), #80 is 1 in (25.40 mm)."
  },
  {
   "q": "How tall are the plates of #40 chain?",
   "a": "At most 0.95 × pitch = 0.475 in (12.07 mm) for the roller-link plates (A-Metric prints 0.472 in); the pin-link plates are lower (0.82 P)."
  },
  {
   "q": "Why do sources disagree on #80 pitch?",
   "a": "One catalogue prints 1.25 in for #80: that is a typo, ANSI #80 is 1 in (8 × 1/8 in)."
  }
 ],
 "files_license": null,
 "offers": [],
 "markdown": "https://xemstudio.com/objects/roller-chain-ansi-b29-1-25-to-80/index.md"
}