{
 "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": "dowel-pins-asme-b18-8-2-inch",
 "name": "Dowel pins, inch (ASME B18.8.2 hardened ground machine dowel pins), 1/16 to 1 in: standard and oversize diameter limits, point diameter, crown",
 "kind": "standard",
 "category": "Hardware",
 "group": "Fasteners",
 "year": null,
 "question": "What are the standard and oversize diameter limits of a 1/4 in dowel pin (ASME B18.8.2)?",
 "tags": [
  "dowel pin",
  "inch dowel pin",
  "asme b18.8.2",
  "hardened ground dowel pin",
  "oversize dowel pin",
  "machine dowel pin",
  "fastener",
  "tool"
 ],
 "aliases": [
  "asme b18.8.2 dowel pin",
  "1/4 dowel pin diameter",
  "1/4 inch dowel pin size .2503",
  "oversize dowel pin .0008",
  "1/8 dowel pin diameter tolerance",
  "3/8 dowel pin diameter",
  "dowel pin sizes inch chart",
  "hardened ground machine dowel pin",
  "5/16 dowel pin diameter",
  "1/2 dowel pin .5003",
  "standard series vs oversize dowel pin"
 ],
 "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/dowel-pins-asme-b18-8-2-inch/",
 "sheet_txt": "https://xemstudio.com/objects/dowel-pins-asme-b18-8-2-inch/sheet.txt",
 "sheet": {
  "basis": "Engineers Edge's ASME B18.8.2 table, checked against the Machinery's Handbook pocket companion table (1/16 to 1/2 in agree on every value read; its 5/8 in row is cut off); numbers only",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "Hardened ground machine dowel pins, ASME B18.8.2, inch, nominal 1/16 to 1 in. Each size has two diameter series: the standard series (for initial installation) and the oversize series (0.0008 in larger, for replacement pins in worn holes), each with a 0.0002 in limit band. Columns: pin diameter max / min for each series in inches (as printed) and in mm (computed, x 25.4), point diameter B max / min and the crown value C max / min, all in inches. Engineers Edge's heading for the last pair is 'crown height C / crown radius R' without saying which the printed column is, so the column is labelled C (crown) and not read further; the Machinery's Handbook text prints the same numbers. The 5/32 in nominal is missing in Engineers Edge's size column and was read from the diameters (0.1565 / 0.1563 in) in both sources.",
   "Length tolerance is ±0.010 in (Engineers Edge's footnote; Amesweb's ASME B18.8.2-2000 page prints the same). Nominal lengths run in 1/16 in steps up to 3/8 in, then 1/8 in, 1/4 in and 1/2 in steps per Engineers Edge's footnote b; the per-size length table was not on the page. The Machinery's Handbook text also prints a double-shear column and a suggested hole range; the column labels did not survive the text extraction, so those values are left out.",
   "Oversize series diameters are exactly 0.0008 in above the standard series (max and min) on every row read. For a nominal 1/4 in pin that is Ø6.358 / 6.353 mm standard against Ø6.378 / 6.373 mm oversize (computed).",
   "Not on this page: unhardened dowel pins, pull-out (tapped) dowels and the metric ISO series (dowel-pins-iso-2338-8734). No file: a dowel is a cylinder with a chamfer or crown, a plain primitive, and the crown height and radius are not separated in the source read.",
   "The existing page dowel-pins-metric covers 2 to 6 mm metric dowels at press and slip hole sizes."
  ],
  "table": {
   "columns": [
    "nominal size",
    "standard series max / min (in)",
    "standard series max / min (mm, computed)",
    "oversize series max / min (in)",
    "oversize series max / min (mm, computed)",
    "point diameter B max / min (in)",
    "crown C max / min (in)"
   ],
   "rows": [
    [
     "1/16 in",
     "0.0628 / 0.0626",
     "1.595 / 1.590",
     "0.0636 / 0.0634",
     "1.615 / 1.610",
     "0.058 / 0.048",
     "0.020 / 0.008"
    ],
    [
     "5/64 in",
     "0.0784 / 0.0782",
     "1.991 / 1.986",
     "0.0792 / 0.0790",
     "2.012 / 2.007",
     "0.074 / 0.064",
     "0.026 / 0.010"
    ],
    [
     "3/32 in",
     "0.0941 / 0.0939",
     "2.390 / 2.385",
     "0.0949 / 0.0947",
     "2.410 / 2.405",
     "0.089 / 0.079",
     "0.031 / 0.012"
    ],
    [
     "1/8 in",
     "0.1253 / 0.1251",
     "3.183 / 3.178",
     "0.1261 / 0.1259",
     "3.203 / 3.198",
     "0.120 / 0.110",
     "0.041 / 0.016"
    ],
    [
     "5/32 in",
     "0.1565 / 0.1563",
     "3.975 / 3.970",
     "0.1573 / 0.1571",
     "3.995 / 3.990",
     "0.150 / 0.140",
     "0.052 / 0.020"
    ],
    [
     "3/16 in",
     "0.1878 / 0.1876",
     "4.770 / 4.765",
     "0.1886 / 0.1884",
     "4.790 / 4.785",
     "0.180 / 0.170",
     "0.062 / 0.023"
    ],
    [
     "1/4 in",
     "0.2503 / 0.2501",
     "6.358 / 6.353",
     "0.2511 / 0.2509",
     "6.378 / 6.373",
     "0.240 / 0.230",
     "0.083 / 0.031"
    ],
    [
     "5/16 in",
     "0.3128 / 0.3126",
     "7.945 / 7.940",
     "0.3136 / 0.3134",
     "7.965 / 7.960",
     "0.302 / 0.290",
     "0.104 / 0.039"
    ],
    [
     "3/8 in",
     "0.3753 / 0.3751",
     "9.533 / 9.528",
     "0.3761 / 0.3759",
     "9.553 / 9.548",
     "0.365 / 0.350",
     "0.125 / 0.047"
    ],
    [
     "7/16 in",
     "0.4378 / 0.4376",
     "11.120 / 11.115",
     "0.4386 / 0.4384",
     "11.140 / 11.135",
     "0.424 / 0.409",
     "0.146 / 0.055"
    ],
    [
     "1/2 in",
     "0.5003 / 0.5001",
     "12.708 / 12.703",
     "0.5011 / 0.5009",
     "12.728 / 12.723",
     "0.486 / 0.471",
     "0.167 / 0.063"
    ],
    [
     "5/8 in",
     "0.6253 / 0.6251",
     "15.883 / 15.878",
     "0.6261 / 0.6259",
     "15.903 / 15.898",
     "0.611 / 0.595",
     "0.208 / 0.078"
    ],
    [
     "3/4 in",
     "0.7503 / 0.7501",
     "19.058 / 19.053",
     "0.7511 / 0.7509",
     "19.078 / 19.073",
     "0.735 / 0.715",
     "0.250 / 0.094"
    ],
    [
     "7/8 in",
     "0.8753 / 0.8751",
     "22.233 / 22.228",
     "0.8761 / 0.8759",
     "22.253 / 22.248",
     "0.860 / 0.840",
     "0.293 / 0.109"
    ],
    [
     "1 in",
     "1.0003 / 1.0001",
     "25.408 / 25.403",
     "1.0011 / 1.0009",
     "25.428 / 25.423",
     "0.980 / 0.960",
     "0.333 / 0.125"
    ]
   ]
  }
 },
 "sheet_text": "Dowel pins, inch (ASME B18.8.2 hardened ground machine dowel pins), 1/16 to 1 in: standard and oversize diameter limits, point diameter, crown — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/dowel-pins-asme-b18-8-2-inch/  (sheet CC BY 4.0)\nBasis: Engineers Edge's ASME B18.8.2 table, checked against the Machinery's Handbook pocket companion table (1/16 to 1/2 in agree on every value read; its 5/8 in row is cut off); numbers only\nCatalog version: 2026-10-20\n\nSizes: see table below\n- Hardened ground machine dowel pins, ASME B18.8.2, inch, nominal 1/16 to 1 in. Each size has two diameter series: the standard series (for initial installation) and the oversize series (0.0008 in larger, for replacement pins in worn holes), each with a 0.0002 in limit band. Columns: pin diameter max / min for each series in inches (as printed) and in mm (computed, x 25.4), point diameter B max / min and the crown value C max / min, all in inches. Engineers Edge's heading for the last pair is 'crown height C / crown radius R' without saying which the printed column is, so the column is labelled C (crown) and not read further; the Machinery's Handbook text prints the same numbers. The 5/32 in nominal is missing in Engineers Edge's size column and was read from the diameters (0.1565 / 0.1563 in) in both sources.\n- Length tolerance is ±0.010 in (Engineers Edge's footnote; Amesweb's ASME B18.8.2-2000 page prints the same). Nominal lengths run in 1/16 in steps up to 3/8 in, then 1/8 in, 1/4 in and 1/2 in steps per Engineers Edge's footnote b; the per-size length table was not on the page. The Machinery's Handbook text also prints a double-shear column and a suggested hole range; the column labels did not survive the text extraction, so those values are left out.\n- Oversize series diameters are exactly 0.0008 in above the standard series (max and min) on every row read. For a nominal 1/4 in pin that is Ø6.358 / 6.353 mm standard against Ø6.378 / 6.373 mm oversize (computed).\n- Not on this page: unhardened dowel pins, pull-out (tapped) dowels and the metric ISO series (dowel-pins-iso-2338-8734). No file: a dowel is a cylinder with a chamfer or crown, a plain primitive, and the crown height and radius are not separated in the source read.\n- The existing page dowel-pins-metric covers 2 to 6 mm metric dowels at press and slip hole sizes.\n\nnominal size  standard series max / min (in)  standard series max / min (mm, computed)  oversize series max / min (in)  oversize series max / min (mm, computed)  point diameter B max / min (in)  crown C max / min (in)\n1/16 in  0.0628 / 0.0626  1.595 / 1.590  0.0636 / 0.0634  1.615 / 1.610  0.058 / 0.048  0.020 / 0.008\n5/64 in  0.0784 / 0.0782  1.991 / 1.986  0.0792 / 0.0790  2.012 / 2.007  0.074 / 0.064  0.026 / 0.010\n3/32 in  0.0941 / 0.0939  2.390 / 2.385  0.0949 / 0.0947  2.410 / 2.405  0.089 / 0.079  0.031 / 0.012\n1/8 in  0.1253 / 0.1251  3.183 / 3.178  0.1261 / 0.1259  3.203 / 3.198  0.120 / 0.110  0.041 / 0.016\n5/32 in  0.1565 / 0.1563  3.975 / 3.970  0.1573 / 0.1571  3.995 / 3.990  0.150 / 0.140  0.052 / 0.020\n3/16 in  0.1878 / 0.1876  4.770 / 4.765  0.1886 / 0.1884  4.790 / 4.785  0.180 / 0.170  0.062 / 0.023\n1/4 in  0.2503 / 0.2501  6.358 / 6.353  0.2511 / 0.2509  6.378 / 6.373  0.240 / 0.230  0.083 / 0.031\n5/16 in  0.3128 / 0.3126  7.945 / 7.940  0.3136 / 0.3134  7.965 / 7.960  0.302 / 0.290  0.104 / 0.039\n3/8 in  0.3753 / 0.3751  9.533 / 9.528  0.3761 / 0.3759  9.553 / 9.548  0.365 / 0.350  0.125 / 0.047\n7/16 in  0.4378 / 0.4376  11.120 / 11.115  0.4386 / 0.4384  11.140 / 11.135  0.424 / 0.409  0.146 / 0.055\n1/2 in  0.5003 / 0.5001  12.708 / 12.703  0.5011 / 0.5009  12.728 / 12.723  0.486 / 0.471  0.167 / 0.063\n5/8 in  0.6253 / 0.6251  15.883 / 15.878  0.6261 / 0.6259  15.903 / 15.898  0.611 / 0.595  0.208 / 0.078\n3/4 in  0.7503 / 0.7501  19.058 / 19.053  0.7511 / 0.7509  19.078 / 19.073  0.735 / 0.715  0.250 / 0.094\n7/8 in  0.8753 / 0.8751  22.233 / 22.228  0.8761 / 0.8759  22.253 / 22.248  0.860 / 0.840  0.293 / 0.109\n1 in  1.0003 / 1.0001  25.408 / 25.403  1.0011 / 1.0009  25.428 / 25.423  0.980 / 0.960  0.333 / 0.125\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Engineers Edge: ANSI / ASME B18.8.2 hardened ground machine dowel pins: standard and oversize series diameter max / min, point diameter B, crown, length footnote, 1/16 to 1 in — web — Reference page; numbers only — https://engineersedge.com/hardware/machine_dowel_pins_chart_ansi_asme__13076.htm\n- Machinery's Handbook pocket companion (GlobalSpec reference): Dowel pins: nominal size, standard and oversize limits, point B, crown, 1/16 to 5/8 in (cross-check; OCR) — web — Reference text; numbers only — https://www.globalspec.com/reference/68241/203279/dowel-pins\n- Amesweb: Dowel pins dimensions (inch): ASME B18.8.2-2000 calculator; length tolerance ±0.01 in (values are interactive and were not readable) — web — Reference page; numbers only — https://Amesweb.info/Fasteners/Pins/Dowel_Pins_Dimensions_Inch.aspx\n- MISUMI: Dowel pins, spring pins, stepped pins (configure a part and download 3D CAD from MISUMI) — web, CAD — Maker site terms; CAD per part from the maker [verify license at link] — https://us.misumi-ec.com/vona2/A0000000001/M1800000000/M1807000000\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=dowel-pins-asme-b18-8-2-inch\n",
 "sources": [
  {
   "publisher": "Engineers Edge",
   "title": "ANSI / ASME B18.8.2 hardened ground machine dowel pins: standard and oversize series diameter max / min, point diameter B, crown, length footnote, 1/16 to 1 in",
   "url": "https://engineersedge.com/hardware/machine_dowel_pins_chart_ansi_asme__13076.htm",
   "formats": [
    "web"
   ],
   "license": "Reference page; numbers only",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Machinery's Handbook pocket companion (GlobalSpec reference)",
   "title": "Dowel pins: nominal size, standard and oversize limits, point B, crown, 1/16 to 5/8 in (cross-check; OCR)",
   "url": "https://www.globalspec.com/reference/68241/203279/dowel-pins",
   "formats": [
    "web"
   ],
   "license": "Reference text; numbers only",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Amesweb",
   "title": "Dowel pins dimensions (inch): ASME B18.8.2-2000 calculator; length tolerance ±0.01 in (values are interactive and were not readable)",
   "url": "https://Amesweb.info/Fasteners/Pins/Dowel_Pins_Dimensions_Inch.aspx",
   "formats": [
    "web"
   ],
   "license": "Reference page; numbers only",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "MISUMI",
   "title": "Dowel pins, spring pins, stepped pins (configure a part and download 3D CAD from MISUMI)",
   "url": "https://us.misumi-ec.com/vona2/A0000000001/M1800000000/M1807000000",
   "formats": [
    "web",
    "CAD"
   ],
   "license": "Maker site terms; CAD per part from the maker",
   "license_verified": false,
   "hosted": false
  }
 ],
 "xem": {
  "status": "not-scanned",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "dowel-pins-iso-2338-8734",
  "dowel-pins-metric",
  "spring-pins-iso-8752-8750-asme-b18-8-2",
  "taper-pins-iso-2339-ansi-b18-8-2",
  "clevis-pins"
 ],
 "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": [],
 "faq": [
  {
   "q": "What diameter is a 1/4 in standard dowel pin?",
   "a": "0.2503 in max and 0.2501 in min (6.358 / 6.353 mm computed) in the ASME B18.8.2 standard series; the oversize series is 0.2511 / 0.2509 in."
  },
  {
   "q": "What is an oversize dowel pin for?",
   "a": "Replacement in a hole that has worn: the oversize series is 0.0008 in larger than the standard series (Engineers Edge's table)."
  },
  {
   "q": "What is the length tolerance of a hardened ground dowel pin?",
   "a": "±0.010 in (Engineers Edge footnote, Amesweb)."
  }
 ],
 "files_license": null,
 "offers": [],
 "markdown": "https://xemstudio.com/objects/dowel-pins-asme-b18-8-2-inch/index.md"
}