{
 "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": "nylon-insert-lock-nuts-inch-asme-b18-16-6",
 "name": "Nylon-insert lock nuts, inch (ASME B18.16.6): 1/4 to 1-1/2 width across flats, across corners, height",
 "kind": "standard",
 "category": "Hardware",
 "group": "Fasteners",
 "year": null,
 "question": "What are the dimensions of a 1/4-20 or 3/8-16 nylon insert lock nut (nylock), and what wrench size does it take?",
 "tags": [
  "nylock nut",
  "nylon insert lock nut",
  "nyloc nut inch",
  "asme b18.16.6",
  "locknut",
  "fastener"
 ],
 "aliases": [
  "1/4-20 nylock nut dimensions",
  "3/8-16 nylon insert lock nut size",
  "nylock nut wrench size",
  "5/16-18 nyloc nut height",
  "1/2-13 nylon lock nut width across flats",
  "asme b18.16.6 table",
  "inch nyloc nut dimensions chart",
  "3/4-10 nylock nut"
 ],
 "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/nylon-insert-lock-nuts-inch-asme-b18-16-6/",
 "sheet_txt": "https://xemstudio.com/objects/nylon-insert-lock-nuts-inch-asme-b18-16-6/sheet.txt",
 "sheet": {
  "basis": "fasten.it's ASME B18.16.6 (2008) Table 1, inch series; numbers only",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "Columns (inches unless stated): threads per inch for coarse (UNC) and fine (UNF) series; B max, C min, D min, E min as the page prints them without defining the letters. B max is the hex width: for 1/4 it is 0.44 in, the 7/16 in (0.4375) across-flats of a 1/4-20 hex nut on hex-nuts-inch, and C min (0.488 for 1/4) is a bit under the across-corners of a 7/16 hex (0.505), so B is read as width across flats and C as across corners. D min (0.298 for 1/4) and E min (0.225) are read as overall height and a lower height of the hex part, but the page does not say so; check the standard before relying on D and E.",
   "The mm column is the nominal size. The 'overall height' of a nylon-insert nut (including the collar) is the number a pocket depth needs; check the maker's drawing for the nut you buy. No file: the collar profile is not published as numbers on the page read, and the hex-prism part is the same as hex-nuts-inch.",
   "Metric nyloc nuts (ISO 7040, DIN 985): nylon-insert-lock-nuts-iso-7040-din-985 and nyloc-nuts-metric. McMaster-Carr sells thin, regular and heavy nylon-insert locknuts with per-part STEP; its category is linked, not copied."
  ],
  "table": {
   "columns": [
    "size (in)",
    "nominal (mm)",
    "UNC TPI",
    "UNF TPI",
    "B max (in)",
    "B max (mm)",
    "C min (in)",
    "D min (in)",
    "E min (in)"
   ],
   "rows": [
    [
     "1/4",
     "6.35",
     "20",
     "28",
     "0.440",
     "11.18",
     "0.488",
     "0.298",
     "0.225"
    ],
    [
     "5/16",
     "7.94",
     "18",
     "24",
     "0.500",
     "12.70",
     "0.557",
     "0.329",
     "0.250"
    ],
    [
     "3/8",
     "9.53",
     "16",
     "24",
     "0.560",
     "14.22",
     "0.628",
     "0.438",
     "0.335"
    ],
    [
     "7/16",
     "11.11",
     "14",
     "20",
     "0.627",
     "15.93",
     "0.698",
     "0.438",
     "0.324"
    ],
    [
     "1/2",
     "12.7",
     "13",
     "20",
     "0.750",
     "19.05",
     "0.840",
     "0.579",
     "0.464"
    ],
    [
     "9/16",
     "14.29",
     "12",
     "18",
     "0.877",
     "22.28",
     "0.980",
     "0.626",
     "0.469"
    ],
    [
     "5/8",
     "15.88",
     "11",
     "18",
     "0.940",
     "23.88",
     "1.050",
     "0.735",
     "0.593"
    ],
    [
     "3/4",
     "19.05",
     "10",
     "16",
     "1.060",
     "26.92",
     "1.190",
     "0.860",
     "0.742"
    ],
    [
     "7/8",
     "22.23",
     "9",
     "14",
     "1.250",
     "31.75",
     "1.400",
     "0.969",
     "0.790"
    ],
    [
     "1",
     "25.4",
     "8",
     "12",
     "1.440",
     "36.58",
     "1.619",
     "1.016",
     "0.825"
    ],
    [
     "1-1/8",
     "28.58",
     "7",
     "12",
     "1.627",
     "41.33",
     "1.830",
     "1.141",
     "0.930"
    ],
    [
     "1-1/4",
     "31.75",
     "7",
     "12",
     "1.815",
     "46.10",
     "2.046",
     "1.360",
     "1.125"
    ],
    [
     "1-3/8",
     "34.93",
     "6",
     "12",
     "2.000",
     "50.80",
     "2.259",
     "1.547",
     "1.282"
    ],
    [
     "1-1/2",
     "38.1",
     "6",
     "12",
     "2.197",
     "55.80",
     "2.470",
     "1.578",
     "1.313"
    ]
   ]
  }
 },
 "sheet_text": "Nylon-insert lock nuts, inch (ASME B18.16.6): 1/4 to 1-1/2 width across flats, across corners, height — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/nylon-insert-lock-nuts-inch-asme-b18-16-6/  (sheet CC BY 4.0)\nBasis: fasten.it's ASME B18.16.6 (2008) Table 1, inch series; numbers only\nCatalog version: 2026-10-20\n\nSizes: see table below\n- Columns (inches unless stated): threads per inch for coarse (UNC) and fine (UNF) series; B max, C min, D min, E min as the page prints them without defining the letters. B max is the hex width: for 1/4 it is 0.44 in, the 7/16 in (0.4375) across-flats of a 1/4-20 hex nut on hex-nuts-inch, and C min (0.488 for 1/4) is a bit under the across-corners of a 7/16 hex (0.505), so B is read as width across flats and C as across corners. D min (0.298 for 1/4) and E min (0.225) are read as overall height and a lower height of the hex part, but the page does not say so; check the standard before relying on D and E.\n- The mm column is the nominal size. The 'overall height' of a nylon-insert nut (including the collar) is the number a pocket depth needs; check the maker's drawing for the nut you buy. No file: the collar profile is not published as numbers on the page read, and the hex-prism part is the same as hex-nuts-inch.\n- Metric nyloc nuts (ISO 7040, DIN 985): nylon-insert-lock-nuts-iso-7040-din-985 and nyloc-nuts-metric. McMaster-Carr sells thin, regular and heavy nylon-insert locknuts with per-part STEP; its category is linked, not copied.\n\nsize (in)  nominal (mm)  UNC TPI  UNF TPI  B max (in)  B max (mm)  C min (in)  D min (in)  E min (in)\n1/4  6.35  20  28  0.440  11.18  0.488  0.298  0.225\n5/16  7.94  18  24  0.500  12.70  0.557  0.329  0.250\n3/8  9.53  16  24  0.560  14.22  0.628  0.438  0.335\n7/16  11.11  14  20  0.627  15.93  0.698  0.438  0.324\n1/2  12.7  13  20  0.750  19.05  0.840  0.579  0.464\n9/16  14.29  12  18  0.877  22.28  0.980  0.626  0.469\n5/8  15.88  11  18  0.940  23.88  1.050  0.735  0.593\n3/4  19.05  10  16  1.060  26.92  1.190  0.860  0.742\n7/8  22.23  9  14  1.250  31.75  1.400  0.969  0.790\n1  25.4  8  12  1.440  36.58  1.619  1.016  0.825\n1-1/8  28.58  7  12  1.627  41.33  1.830  1.141  0.930\n1-1/4  31.75  7  12  1.815  46.10  2.046  1.360  1.125\n1-3/8  34.93  6  12  2.000  50.80  2.259  1.547  1.282\n1-1/2  38.1  6  12  2.197  55.80  2.470  1.578  1.313\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- fasten.it: ASME B18.16.6 nylon insert lock nuts, inch series (2008) Table 1: B max, C min, D min, E min; 1/4 to 1-1/2 — web — Reference page; numbers only. The page does not define the column letters — https://www.fasten.it/norms/norm/asme_b18.16.6\n- McMaster-Carr: Locknuts (nylon-insert, thin and heavy profiles) (free STEP/IGES per part, for your own design use; no redistribution) — STEP, IGES, PDF — McMaster-Carr site terms: personal design use, no redistribution [verify license at link] — https://www.mcmaster.com/products/locknuts/hex-nut-profile~thin-heavy/\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=nylon-insert-lock-nuts-inch-asme-b18-16-6\n",
 "sources": [
  {
   "publisher": "fasten.it",
   "title": "ASME B18.16.6 nylon insert lock nuts, inch series (2008) Table 1: B max, C min, D min, E min; 1/4 to 1-1/2",
   "url": "https://www.fasten.it/norms/norm/asme_b18.16.6",
   "formats": [
    "web"
   ],
   "license": "Reference page; numbers only. The page does not define the column letters",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "McMaster-Carr",
   "title": "Locknuts (nylon-insert, thin and heavy profiles) (free STEP/IGES per part, for your own design use; no redistribution)",
   "url": "https://www.mcmaster.com/products/locknuts/hex-nut-profile~thin-heavy/",
   "formats": [
    "STEP",
    "IGES",
    "PDF"
   ],
   "license": "McMaster-Carr site terms: personal design use, no redistribution",
   "license_verified": false,
   "hosted": false
  }
 ],
 "xem": {
  "status": "not-scanned",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "hex-nuts-inch",
  "nylon-insert-lock-nuts-iso-7040-din-985",
  "nyloc-nuts-metric",
  "flat-washers-inch",
  "plain-washers-inch-type-b"
 ],
 "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 wrench size is a 3/8-16 nylock nut?",
   "a": "B max is 0.56 in (9/16 in) in the ASME B18.16.6 table at fasten.it, matching the 9/16 in hex nut on hex-nuts-inch."
  },
  {
   "q": "How tall is a 1/4-20 nylon insert lock nut?",
   "a": "The table's D min is 0.298 in and E min 0.225 in; the page does not define the letters, so check the standard."
  }
 ],
 "files_license": null,
 "offers": [],
 "markdown": "https://xemstudio.com/objects/nylon-insert-lock-nuts-inch-asme-b18-16-6/index.md"
}