{
 "meta": {
  "dataset": "threads",
  "description": "UNC/UNF and ISO metric threads with tap drills and clearance holes.",
  "schema_version": "1",
  "generated": "2026-08-12",
  "records": 65,
  "license": "CC BY 4.0 — attribution: BenchReference (benchreference.com)",
  "sources": [
   "asme-b1-1",
   "iso-261",
   "machinerys-handbook",
   "asme-b18-2-8",
   "iso-273"
  ],
  "provenance": "https://benchreference.com/sources/"
 },
 "entries": [
  {
   "designation": "#1-64 UNC",
   "family": "UNC",
   "major_inches": 0.073,
   "major_mm": 1.8541999999999998,
   "tpi": 64,
   "pitch_mm": 0.396875,
   "tap_drill": "#53",
   "tap_drill_inches": 0.0595,
   "clearance_close": "#46",
   "clearance_normal": "#43",
   "clearance_loose": "#37"
  },
  {
   "designation": "#2-56 UNC",
   "family": "UNC",
   "major_inches": 0.086,
   "major_mm": 2.1843999999999997,
   "tpi": 56,
   "pitch_mm": 0.4535714285714285,
   "tap_drill": "#50",
   "tap_drill_inches": 0.07,
   "clearance_close": "3/32″",
   "clearance_normal": "#38",
   "clearance_loose": "#32"
  },
  {
   "designation": "#3-48 UNC",
   "family": "UNC",
   "major_inches": 0.099,
   "major_mm": 2.5146,
   "tpi": 48,
   "pitch_mm": 0.5291666666666666,
   "tap_drill": "#47",
   "tap_drill_inches": 0.0785,
   "clearance_close": "#36",
   "clearance_normal": "#32",
   "clearance_loose": "#30"
  },
  {
   "designation": "#4-40 UNC",
   "family": "UNC",
   "major_inches": 0.112,
   "major_mm": 2.8447999999999998,
   "tpi": 40,
   "pitch_mm": 0.635,
   "tap_drill": "#43",
   "tap_drill_inches": 0.089,
   "clearance_close": "#31",
   "clearance_normal": "#30",
   "clearance_loose": "#27"
  },
  {
   "designation": "#5-40 UNC",
   "family": "UNC",
   "major_inches": 0.125,
   "major_mm": 3.175,
   "tpi": 40,
   "pitch_mm": 0.635,
   "tap_drill": "#38",
   "tap_drill_inches": 0.1015,
   "clearance_close": "9/64″",
   "clearance_normal": "5/32″",
   "clearance_loose": "11/64″"
  },
  {
   "designation": "#6-32 UNC",
   "family": "UNC",
   "major_inches": 0.138,
   "major_mm": 3.5052000000000003,
   "tpi": 32,
   "pitch_mm": 0.79375,
   "tap_drill": "#36",
   "tap_drill_inches": 0.1065,
   "clearance_close": "#23",
   "clearance_normal": "#18",
   "clearance_loose": "#13"
  },
  {
   "designation": "#8-32 UNC",
   "family": "UNC",
   "major_inches": 0.164,
   "major_mm": 4.1655999999999995,
   "tpi": 32,
   "pitch_mm": 0.79375,
   "tap_drill": "#29",
   "tap_drill_inches": 0.136,
   "clearance_close": "#15",
   "clearance_normal": "#9",
   "clearance_loose": "#3"
  },
  {
   "designation": "#10-24 UNC",
   "family": "UNC",
   "major_inches": 0.19,
   "major_mm": 4.826,
   "tpi": 24,
   "pitch_mm": 1.0583333333333331,
   "tap_drill": "#25",
   "tap_drill_inches": 0.1495,
   "clearance_close": "#5",
   "clearance_normal": "#2",
   "clearance_loose": "B"
  },
  {
   "designation": "#12-24 UNC",
   "family": "UNC",
   "major_inches": 0.216,
   "major_mm": 5.4864,
   "tpi": 24,
   "pitch_mm": 1.0583333333333331,
   "tap_drill": "#16",
   "tap_drill_inches": 0.177,
   "clearance_close": null,
   "clearance_normal": null,
   "clearance_loose": null
  },
  {
   "designation": "1/4″-20 UNC",
   "family": "UNC",
   "major_inches": 0.25,
   "major_mm": 6.35,
   "tpi": 20,
   "pitch_mm": 1.27,
   "tap_drill": "#7",
   "tap_drill_inches": 0.201,
   "clearance_close": "17/64″",
   "clearance_normal": "9/32″",
   "clearance_loose": "19/64″"
  },
  {
   "designation": "5/16″-18 UNC",
   "family": "UNC",
   "major_inches": 0.3125,
   "major_mm": 7.9375,
   "tpi": 18,
   "pitch_mm": 1.411111111111111,
   "tap_drill": "F",
   "tap_drill_inches": 0.257,
   "clearance_close": "21/64″",
   "clearance_normal": "11/32″",
   "clearance_loose": "23/64″"
  },
  {
   "designation": "3/8″-16 UNC",
   "family": "UNC",
   "major_inches": 0.375,
   "major_mm": 9.524999999999999,
   "tpi": 16,
   "pitch_mm": 1.5875,
   "tap_drill": "5/16″",
   "tap_drill_inches": 0.3125,
   "clearance_close": "25/64″",
   "clearance_normal": "13/32″",
   "clearance_loose": "27/64″"
  },
  {
   "designation": "7/16″-14 UNC",
   "family": "UNC",
   "major_inches": 0.4375,
   "major_mm": 11.112499999999999,
   "tpi": 14,
   "pitch_mm": 1.814285714285714,
   "tap_drill": "U",
   "tap_drill_inches": 0.368,
   "clearance_close": "29/64″",
   "clearance_normal": "15/32″",
   "clearance_loose": "31/64″"
  },
  {
   "designation": "1/2″-13 UNC",
   "family": "UNC",
   "major_inches": 0.5,
   "major_mm": 12.7,
   "tpi": 13,
   "pitch_mm": 1.9538461538461538,
   "tap_drill": "27/64″",
   "tap_drill_inches": 0.421875,
   "clearance_close": "17/32″",
   "clearance_normal": "9/16″",
   "clearance_loose": "39/64″"
  },
  {
   "designation": "9/16″-12 UNC",
   "family": "UNC",
   "major_inches": 0.5625,
   "major_mm": 14.2875,
   "tpi": 12,
   "pitch_mm": 2.1166666666666663,
   "tap_drill": "31/64″",
   "tap_drill_inches": 0.484375,
   "clearance_close": null,
   "clearance_normal": null,
   "clearance_loose": null
  },
  {
   "designation": "5/8″-11 UNC",
   "family": "UNC",
   "major_inches": 0.625,
   "major_mm": 15.875,
   "tpi": 11,
   "pitch_mm": 2.309090909090909,
   "tap_drill": "17/32″",
   "tap_drill_inches": 0.53125,
   "clearance_close": "21/32″",
   "clearance_normal": "11/16″",
   "clearance_loose": "47/64″"
  },
  {
   "designation": "3/4″-10 UNC",
   "family": "UNC",
   "major_inches": 0.75,
   "major_mm": 19.049999999999997,
   "tpi": 10,
   "pitch_mm": 2.54,
   "tap_drill": "21/32″",
   "tap_drill_inches": 0.65625,
   "clearance_close": "25/32″",
   "clearance_normal": "13/16″",
   "clearance_loose": "29/32″"
  },
  {
   "designation": "7/8″-9 UNC",
   "family": "UNC",
   "major_inches": 0.875,
   "major_mm": 22.224999999999998,
   "tpi": 9,
   "pitch_mm": 2.822222222222222,
   "tap_drill": "49/64″",
   "tap_drill_inches": 0.765625,
   "clearance_close": "29/32″",
   "clearance_normal": "15/16″",
   "clearance_loose": "1-1/32″"
  },
  {
   "designation": "1″-8 UNC",
   "family": "UNC",
   "major_inches": 1,
   "major_mm": 25.4,
   "tpi": 8,
   "pitch_mm": 3.175,
   "tap_drill": "7/8″",
   "tap_drill_inches": 0.875,
   "clearance_close": "1-1/32″",
   "clearance_normal": "1-3/32″",
   "clearance_loose": "1-5/32″"
  },
  {
   "designation": "#0-80 UNF",
   "family": "UNF",
   "major_inches": 0.06,
   "major_mm": 1.5239999999999998,
   "tpi": 80,
   "pitch_mm": 0.3175,
   "tap_drill": "3/64″",
   "tap_drill_inches": 0.046875,
   "clearance_close": "#51",
   "clearance_normal": "#48",
   "clearance_loose": "3/32″"
  },
  {
   "designation": "#1-72 UNF",
   "family": "UNF",
   "major_inches": 0.073,
   "major_mm": 1.8541999999999998,
   "tpi": 72,
   "pitch_mm": 0.35277777777777775,
   "tap_drill": "#53",
   "tap_drill_inches": 0.0595,
   "clearance_close": "#46",
   "clearance_normal": "#43",
   "clearance_loose": "#37"
  },
  {
   "designation": "#2-64 UNF",
   "family": "UNF",
   "major_inches": 0.086,
   "major_mm": 2.1843999999999997,
   "tpi": 64,
   "pitch_mm": 0.396875,
   "tap_drill": "#50",
   "tap_drill_inches": 0.07,
   "clearance_close": "3/32″",
   "clearance_normal": "#38",
   "clearance_loose": "#32"
  },
  {
   "designation": "#3-56 UNF",
   "family": "UNF",
   "major_inches": 0.099,
   "major_mm": 2.5146,
   "tpi": 56,
   "pitch_mm": 0.4535714285714285,
   "tap_drill": "#45",
   "tap_drill_inches": 0.082,
   "clearance_close": "#36",
   "clearance_normal": "#32",
   "clearance_loose": "#30"
  },
  {
   "designation": "#4-48 UNF",
   "family": "UNF",
   "major_inches": 0.112,
   "major_mm": 2.8447999999999998,
   "tpi": 48,
   "pitch_mm": 0.5291666666666666,
   "tap_drill": "#42",
   "tap_drill_inches": 0.0935,
   "clearance_close": "#31",
   "clearance_normal": "#30",
   "clearance_loose": "#27"
  },
  {
   "designation": "#5-44 UNF",
   "family": "UNF",
   "major_inches": 0.125,
   "major_mm": 3.175,
   "tpi": 44,
   "pitch_mm": 0.5772727272727273,
   "tap_drill": "#37",
   "tap_drill_inches": 0.104,
   "clearance_close": "9/64″",
   "clearance_normal": "5/32″",
   "clearance_loose": "11/64″"
  },
  {
   "designation": "#6-40 UNF",
   "family": "UNF",
   "major_inches": 0.138,
   "major_mm": 3.5052000000000003,
   "tpi": 40,
   "pitch_mm": 0.635,
   "tap_drill": "#33",
   "tap_drill_inches": 0.113,
   "clearance_close": "#23",
   "clearance_normal": "#18",
   "clearance_loose": "#13"
  },
  {
   "designation": "#8-36 UNF",
   "family": "UNF",
   "major_inches": 0.164,
   "major_mm": 4.1655999999999995,
   "tpi": 36,
   "pitch_mm": 0.7055555555555555,
   "tap_drill": "#29",
   "tap_drill_inches": 0.136,
   "clearance_close": "#15",
   "clearance_normal": "#9",
   "clearance_loose": "#3"
  },
  {
   "designation": "#10-32 UNF",
   "family": "UNF",
   "major_inches": 0.19,
   "major_mm": 4.826,
   "tpi": 32,
   "pitch_mm": 0.79375,
   "tap_drill": "#21",
   "tap_drill_inches": 0.159,
   "clearance_close": "#5",
   "clearance_normal": "#2",
   "clearance_loose": "B"
  },
  {
   "designation": "#12-28 UNF",
   "family": "UNF",
   "major_inches": 0.216,
   "major_mm": 5.4864,
   "tpi": 28,
   "pitch_mm": 0.907142857142857,
   "tap_drill": "#14",
   "tap_drill_inches": 0.182,
   "clearance_close": null,
   "clearance_normal": null,
   "clearance_loose": null
  },
  {
   "designation": "1/4″-28 UNF",
   "family": "UNF",
   "major_inches": 0.25,
   "major_mm": 6.35,
   "tpi": 28,
   "pitch_mm": 0.907142857142857,
   "tap_drill": "#3",
   "tap_drill_inches": 0.213,
   "clearance_close": "17/64″",
   "clearance_normal": "9/32″",
   "clearance_loose": "19/64″"
  },
  {
   "designation": "5/16″-24 UNF",
   "family": "UNF",
   "major_inches": 0.3125,
   "major_mm": 7.9375,
   "tpi": 24,
   "pitch_mm": 1.0583333333333331,
   "tap_drill": "I",
   "tap_drill_inches": 0.272,
   "clearance_close": "21/64″",
   "clearance_normal": "11/32″",
   "clearance_loose": "23/64″"
  },
  {
   "designation": "3/8″-24 UNF",
   "family": "UNF",
   "major_inches": 0.375,
   "major_mm": 9.524999999999999,
   "tpi": 24,
   "pitch_mm": 1.0583333333333331,
   "tap_drill": "Q",
   "tap_drill_inches": 0.332,
   "clearance_close": "25/64″",
   "clearance_normal": "13/32″",
   "clearance_loose": "27/64″"
  },
  {
   "designation": "7/16″-20 UNF",
   "family": "UNF",
   "major_inches": 0.4375,
   "major_mm": 11.112499999999999,
   "tpi": 20,
   "pitch_mm": 1.27,
   "tap_drill": "25/64″",
   "tap_drill_inches": 0.390625,
   "clearance_close": "29/64″",
   "clearance_normal": "15/32″",
   "clearance_loose": "31/64″"
  },
  {
   "designation": "1/2″-20 UNF",
   "family": "UNF",
   "major_inches": 0.5,
   "major_mm": 12.7,
   "tpi": 20,
   "pitch_mm": 1.27,
   "tap_drill": "29/64″",
   "tap_drill_inches": 0.453125,
   "clearance_close": "17/32″",
   "clearance_normal": "9/16″",
   "clearance_loose": "39/64″"
  },
  {
   "designation": "9/16″-18 UNF",
   "family": "UNF",
   "major_inches": 0.5625,
   "major_mm": 14.2875,
   "tpi": 18,
   "pitch_mm": 1.411111111111111,
   "tap_drill": "33/64″",
   "tap_drill_inches": 0.515625,
   "clearance_close": null,
   "clearance_normal": null,
   "clearance_loose": null
  },
  {
   "designation": "5/8″-18 UNF",
   "family": "UNF",
   "major_inches": 0.625,
   "major_mm": 15.875,
   "tpi": 18,
   "pitch_mm": 1.411111111111111,
   "tap_drill": "37/64″",
   "tap_drill_inches": 0.578125,
   "clearance_close": "21/32″",
   "clearance_normal": "11/16″",
   "clearance_loose": "47/64″"
  },
  {
   "designation": "3/4″-16 UNF",
   "family": "UNF",
   "major_inches": 0.75,
   "major_mm": 19.049999999999997,
   "tpi": 16,
   "pitch_mm": 1.5875,
   "tap_drill": "11/16″",
   "tap_drill_inches": 0.6875,
   "clearance_close": "25/32″",
   "clearance_normal": "13/16″",
   "clearance_loose": "29/32″"
  },
  {
   "designation": "7/8″-14 UNF",
   "family": "UNF",
   "major_inches": 0.875,
   "major_mm": 22.224999999999998,
   "tpi": 14,
   "pitch_mm": 1.814285714285714,
   "tap_drill": "13/16″",
   "tap_drill_inches": 0.8125,
   "clearance_close": "29/32″",
   "clearance_normal": "15/16″",
   "clearance_loose": "1-1/32″"
  },
  {
   "designation": "1″-12 UNF",
   "family": "UNF",
   "major_inches": 1,
   "major_mm": 25.4,
   "tpi": 12,
   "pitch_mm": 2.1166666666666663,
   "tap_drill": "59/64″",
   "tap_drill_inches": 0.921875,
   "clearance_close": "1-1/32″",
   "clearance_normal": "1-3/32″",
   "clearance_loose": "1-5/32″"
  },
  {
   "designation": "M1.6 × 0.35",
   "family": "metric-coarse",
   "major_inches": 0.06299212598425198,
   "major_mm": 1.6,
   "tpi": null,
   "pitch_mm": 0.35,
   "tap_drill": "1.25 mm",
   "tap_drill_inches": 0.04921259842519685,
   "clearance_close": "1.7 mm",
   "clearance_normal": "1.8 mm",
   "clearance_loose": "2 mm"
  },
  {
   "designation": "M2 × 0.4",
   "family": "metric-coarse",
   "major_inches": 0.07874015748031496,
   "major_mm": 2,
   "tpi": null,
   "pitch_mm": 0.4,
   "tap_drill": "1.6 mm",
   "tap_drill_inches": 0.06299212598425198,
   "clearance_close": "2.2 mm",
   "clearance_normal": "2.4 mm",
   "clearance_loose": "2.6 mm"
  },
  {
   "designation": "M2.5 × 0.45",
   "family": "metric-coarse",
   "major_inches": 0.0984251968503937,
   "major_mm": 2.5,
   "tpi": null,
   "pitch_mm": 0.45,
   "tap_drill": "2.05 mm",
   "tap_drill_inches": 0.08070866141732283,
   "clearance_close": "2.7 mm",
   "clearance_normal": "2.9 mm",
   "clearance_loose": "3.1 mm"
  },
  {
   "designation": "M3 × 0.5",
   "family": "metric-coarse",
   "major_inches": 0.11811023622047245,
   "major_mm": 3,
   "tpi": null,
   "pitch_mm": 0.5,
   "tap_drill": "2.5 mm",
   "tap_drill_inches": 0.0984251968503937,
   "clearance_close": "3.2 mm",
   "clearance_normal": "3.4 mm",
   "clearance_loose": "3.6 mm"
  },
  {
   "designation": "M3.5 × 0.6",
   "family": "metric-coarse",
   "major_inches": 0.1377952755905512,
   "major_mm": 3.5,
   "tpi": null,
   "pitch_mm": 0.6,
   "tap_drill": "2.9 mm",
   "tap_drill_inches": 0.1141732283464567,
   "clearance_close": "3.7 mm",
   "clearance_normal": "3.9 mm",
   "clearance_loose": "4.2 mm"
  },
  {
   "designation": "M4 × 0.7",
   "family": "metric-coarse",
   "major_inches": 0.15748031496062992,
   "major_mm": 4,
   "tpi": null,
   "pitch_mm": 0.7,
   "tap_drill": "3.3 mm",
   "tap_drill_inches": 0.12992125984251968,
   "clearance_close": "4.3 mm",
   "clearance_normal": "4.5 mm",
   "clearance_loose": "4.8 mm"
  },
  {
   "designation": "M5 × 0.8",
   "family": "metric-coarse",
   "major_inches": 0.1968503937007874,
   "major_mm": 5,
   "tpi": null,
   "pitch_mm": 0.8,
   "tap_drill": "4.2 mm",
   "tap_drill_inches": 0.16535433070866143,
   "clearance_close": "5.3 mm",
   "clearance_normal": "5.5 mm",
   "clearance_loose": "5.8 mm"
  },
  {
   "designation": "M6 × 1",
   "family": "metric-coarse",
   "major_inches": 0.2362204724409449,
   "major_mm": 6,
   "tpi": null,
   "pitch_mm": 1,
   "tap_drill": "5 mm",
   "tap_drill_inches": 0.1968503937007874,
   "clearance_close": "6.4 mm",
   "clearance_normal": "6.6 mm",
   "clearance_loose": "7 mm"
  },
  {
   "designation": "M8 × 1.25",
   "family": "metric-coarse",
   "major_inches": 0.31496062992125984,
   "major_mm": 8,
   "tpi": null,
   "pitch_mm": 1.25,
   "tap_drill": "6.8 mm",
   "tap_drill_inches": 0.2677165354330709,
   "clearance_close": "8.4 mm",
   "clearance_normal": "9 mm",
   "clearance_loose": "10 mm"
  },
  {
   "designation": "M10 × 1.5",
   "family": "metric-coarse",
   "major_inches": 0.3937007874015748,
   "major_mm": 10,
   "tpi": null,
   "pitch_mm": 1.5,
   "tap_drill": "8.5 mm",
   "tap_drill_inches": 0.3346456692913386,
   "clearance_close": "10.5 mm",
   "clearance_normal": "11 mm",
   "clearance_loose": "12 mm"
  },
  {
   "designation": "M12 × 1.75",
   "family": "metric-coarse",
   "major_inches": 0.4724409448818898,
   "major_mm": 12,
   "tpi": null,
   "pitch_mm": 1.75,
   "tap_drill": "10.2 mm",
   "tap_drill_inches": 0.4015748031496063,
   "clearance_close": "13 mm",
   "clearance_normal": "13.5 mm",
   "clearance_loose": "14.5 mm"
  },
  {
   "designation": "M14 × 2",
   "family": "metric-coarse",
   "major_inches": 0.5511811023622047,
   "major_mm": 14,
   "tpi": null,
   "pitch_mm": 2,
   "tap_drill": "12 mm",
   "tap_drill_inches": 0.4724409448818898,
   "clearance_close": "15 mm",
   "clearance_normal": "15.5 mm",
   "clearance_loose": "16.5 mm"
  },
  {
   "designation": "M16 × 2",
   "family": "metric-coarse",
   "major_inches": 0.6299212598425197,
   "major_mm": 16,
   "tpi": null,
   "pitch_mm": 2,
   "tap_drill": "14 mm",
   "tap_drill_inches": 0.5511811023622047,
   "clearance_close": "17 mm",
   "clearance_normal": "17.5 mm",
   "clearance_loose": "18.5 mm"
  },
  {
   "designation": "M18 × 2.5",
   "family": "metric-coarse",
   "major_inches": 0.7086614173228347,
   "major_mm": 18,
   "tpi": null,
   "pitch_mm": 2.5,
   "tap_drill": "15.5 mm",
   "tap_drill_inches": 0.610236220472441,
   "clearance_close": "19 mm",
   "clearance_normal": "20 mm",
   "clearance_loose": "21 mm"
  },
  {
   "designation": "M20 × 2.5",
   "family": "metric-coarse",
   "major_inches": 0.7874015748031497,
   "major_mm": 20,
   "tpi": null,
   "pitch_mm": 2.5,
   "tap_drill": "17.5 mm",
   "tap_drill_inches": 0.6889763779527559,
   "clearance_close": "21 mm",
   "clearance_normal": "22 mm",
   "clearance_loose": "24 mm"
  },
  {
   "designation": "M22 × 2.5",
   "family": "metric-coarse",
   "major_inches": 0.8661417322834646,
   "major_mm": 22,
   "tpi": null,
   "pitch_mm": 2.5,
   "tap_drill": "19.5 mm",
   "tap_drill_inches": 0.767716535433071,
   "clearance_close": "23 mm",
   "clearance_normal": "24 mm",
   "clearance_loose": "26 mm"
  },
  {
   "designation": "M24 × 3",
   "family": "metric-coarse",
   "major_inches": 0.9448818897637796,
   "major_mm": 24,
   "tpi": null,
   "pitch_mm": 3,
   "tap_drill": "21 mm",
   "tap_drill_inches": 0.8267716535433072,
   "clearance_close": "25 mm",
   "clearance_normal": "26 mm",
   "clearance_loose": "28 mm"
  },
  {
   "designation": "M8 × 1",
   "family": "metric-fine",
   "major_inches": 0.31496062992125984,
   "major_mm": 8,
   "tpi": null,
   "pitch_mm": 1,
   "tap_drill": "7 mm",
   "tap_drill_inches": 0.2755905511811024,
   "clearance_close": "8.4 mm",
   "clearance_normal": "9 mm",
   "clearance_loose": "10 mm"
  },
  {
   "designation": "M10 × 1",
   "family": "metric-fine",
   "major_inches": 0.3937007874015748,
   "major_mm": 10,
   "tpi": null,
   "pitch_mm": 1,
   "tap_drill": "9 mm",
   "tap_drill_inches": 0.35433070866141736,
   "clearance_close": "10.5 mm",
   "clearance_normal": "11 mm",
   "clearance_loose": "12 mm"
  },
  {
   "designation": "M10 × 1.25",
   "family": "metric-fine",
   "major_inches": 0.3937007874015748,
   "major_mm": 10,
   "tpi": null,
   "pitch_mm": 1.25,
   "tap_drill": "8.8 mm",
   "tap_drill_inches": 0.3464566929133859,
   "clearance_close": "10.5 mm",
   "clearance_normal": "11 mm",
   "clearance_loose": "12 mm"
  },
  {
   "designation": "M12 × 1.25",
   "family": "metric-fine",
   "major_inches": 0.4724409448818898,
   "major_mm": 12,
   "tpi": null,
   "pitch_mm": 1.25,
   "tap_drill": "10.8 mm",
   "tap_drill_inches": 0.42519685039370086,
   "clearance_close": "13 mm",
   "clearance_normal": "13.5 mm",
   "clearance_loose": "14.5 mm"
  },
  {
   "designation": "M12 × 1.5",
   "family": "metric-fine",
   "major_inches": 0.4724409448818898,
   "major_mm": 12,
   "tpi": null,
   "pitch_mm": 1.5,
   "tap_drill": "10.5 mm",
   "tap_drill_inches": 0.4133858267716536,
   "clearance_close": "13 mm",
   "clearance_normal": "13.5 mm",
   "clearance_loose": "14.5 mm"
  },
  {
   "designation": "M14 × 1.5",
   "family": "metric-fine",
   "major_inches": 0.5511811023622047,
   "major_mm": 14,
   "tpi": null,
   "pitch_mm": 1.5,
   "tap_drill": "12.5 mm",
   "tap_drill_inches": 0.4921259842519685,
   "clearance_close": "15 mm",
   "clearance_normal": "15.5 mm",
   "clearance_loose": "16.5 mm"
  },
  {
   "designation": "M16 × 1.5",
   "family": "metric-fine",
   "major_inches": 0.6299212598425197,
   "major_mm": 16,
   "tpi": null,
   "pitch_mm": 1.5,
   "tap_drill": "14.5 mm",
   "tap_drill_inches": 0.5708661417322834,
   "clearance_close": "17 mm",
   "clearance_normal": "17.5 mm",
   "clearance_loose": "18.5 mm"
  },
  {
   "designation": "M18 × 1.5",
   "family": "metric-fine",
   "major_inches": 0.7086614173228347,
   "major_mm": 18,
   "tpi": null,
   "pitch_mm": 1.5,
   "tap_drill": "16.5 mm",
   "tap_drill_inches": 0.6496062992125985,
   "clearance_close": "19 mm",
   "clearance_normal": "20 mm",
   "clearance_loose": "21 mm"
  },
  {
   "designation": "M20 × 1.5",
   "family": "metric-fine",
   "major_inches": 0.7874015748031497,
   "major_mm": 20,
   "tpi": null,
   "pitch_mm": 1.5,
   "tap_drill": "18.5 mm",
   "tap_drill_inches": 0.7283464566929134,
   "clearance_close": "21 mm",
   "clearance_normal": "22 mm",
   "clearance_loose": "24 mm"
  }
 ]
}