{
 "meta": {
  "title": "Socket Size Chart",
  "rows": 31,
  "sources": [
   "ASME B18.2.1 / B18.2.2 (inch hex bolts and nuts)",
   "ISO 4014 / ISO 4032 (metric hex bolts and nuts)",
   "DIN 931 (legacy metric widths, where different)"
  ],
  "derived": "Millimetre/inch conversions, SAE-to-metric differences and interchangeability verdicts are computed.",
  "interchange_rule": "Under 0.6% difference: interchangeable. 0.6-1.5%: usable but sloppy. Over 1.5%: expect to round the fastener.",
  "key_fact": "M10, M12, M14 and M22 have different across-flats sizes under ISO 4014 than under the older DIN 931 \u2014 the reason a metric set sometimes seems to be missing a size."
 },
 "columns": [
  "fastener",
  "system",
  "socket",
  "across_flats_in",
  "across_flats_mm",
  "legacy_note"
 ],
 "rows": [
  {
   "fastener": "#6",
   "system": "Inch (SAE)",
   "socket": "5/16\"",
   "across_flats_in": 0.3125,
   "across_flats_mm": 7.94,
   "legacy_note": ""
  },
  {
   "fastener": "#8",
   "system": "Inch (SAE)",
   "socket": "11/32\"",
   "across_flats_in": 0.3438,
   "across_flats_mm": 8.73,
   "legacy_note": ""
  },
  {
   "fastener": "#10",
   "system": "Inch (SAE)",
   "socket": "3/8\"",
   "across_flats_in": 0.375,
   "across_flats_mm": 9.52,
   "legacy_note": ""
  },
  {
   "fastener": "1/4",
   "system": "Inch (SAE)",
   "socket": "7/16\"",
   "across_flats_in": 0.4375,
   "across_flats_mm": 11.11,
   "legacy_note": ""
  },
  {
   "fastener": "5/16",
   "system": "Inch (SAE)",
   "socket": "1/2\"",
   "across_flats_in": 0.5,
   "across_flats_mm": 12.7,
   "legacy_note": ""
  },
  {
   "fastener": "3/8",
   "system": "Inch (SAE)",
   "socket": "9/16\"",
   "across_flats_in": 0.5625,
   "across_flats_mm": 14.29,
   "legacy_note": ""
  },
  {
   "fastener": "7/16",
   "system": "Inch (SAE)",
   "socket": "5/8\"",
   "across_flats_in": 0.625,
   "across_flats_mm": 15.88,
   "legacy_note": ""
  },
  {
   "fastener": "1/2",
   "system": "Inch (SAE)",
   "socket": "3/4\"",
   "across_flats_in": 0.75,
   "across_flats_mm": 19.05,
   "legacy_note": ""
  },
  {
   "fastener": "9/16",
   "system": "Inch (SAE)",
   "socket": "13/16\"",
   "across_flats_in": 0.8125,
   "across_flats_mm": 20.64,
   "legacy_note": ""
  },
  {
   "fastener": "5/8",
   "system": "Inch (SAE)",
   "socket": "15/16\"",
   "across_flats_in": 0.9375,
   "across_flats_mm": 23.81,
   "legacy_note": ""
  },
  {
   "fastener": "3/4",
   "system": "Inch (SAE)",
   "socket": "1-1/8\"",
   "across_flats_in": 1.125,
   "across_flats_mm": 28.57,
   "legacy_note": ""
  },
  {
   "fastener": "7/8",
   "system": "Inch (SAE)",
   "socket": "1-5/16\"",
   "across_flats_in": 1.3125,
   "across_flats_mm": 33.34,
   "legacy_note": ""
  },
  {
   "fastener": "1",
   "system": "Inch (SAE)",
   "socket": "1-1/2\"",
   "across_flats_in": 1.5,
   "across_flats_mm": 38.1,
   "legacy_note": ""
  },
  {
   "fastener": "1-1/8",
   "system": "Inch (SAE)",
   "socket": "1-11/16\"",
   "across_flats_in": 1.6875,
   "across_flats_mm": 42.86,
   "legacy_note": ""
  },
  {
   "fastener": "1-1/4",
   "system": "Inch (SAE)",
   "socket": "1-7/8\"",
   "across_flats_in": 1.875,
   "across_flats_mm": 47.62,
   "legacy_note": ""
  },
  {
   "fastener": "1-1/2",
   "system": "Inch (SAE)",
   "socket": "2-1/4\"",
   "across_flats_in": 2.25,
   "across_flats_mm": 57.15,
   "legacy_note": ""
  },
  {
   "fastener": "M3",
   "system": "Metric",
   "socket": "5.5 mm",
   "across_flats_in": 0.2165,
   "across_flats_mm": 5.5,
   "legacy_note": ""
  },
  {
   "fastener": "M4",
   "system": "Metric",
   "socket": "7 mm",
   "across_flats_in": 0.2756,
   "across_flats_mm": 7,
   "legacy_note": ""
  },
  {
   "fastener": "M5",
   "system": "Metric",
   "socket": "8 mm",
   "across_flats_in": 0.315,
   "across_flats_mm": 8,
   "legacy_note": ""
  },
  {
   "fastener": "M6",
   "system": "Metric",
   "socket": "10 mm",
   "across_flats_in": 0.3937,
   "across_flats_mm": 10,
   "legacy_note": ""
  },
  {
   "fastener": "M8",
   "system": "Metric",
   "socket": "13 mm",
   "across_flats_in": 0.5118,
   "across_flats_mm": 13,
   "legacy_note": ""
  },
  {
   "fastener": "M10",
   "system": "Metric",
   "socket": "16 mm",
   "across_flats_in": 0.6299,
   "across_flats_mm": 16,
   "legacy_note": "DIN 931 uses 17 mm"
  },
  {
   "fastener": "M12",
   "system": "Metric",
   "socket": "18 mm",
   "across_flats_in": 0.7087,
   "across_flats_mm": 18,
   "legacy_note": "DIN 931 uses 19 mm"
  },
  {
   "fastener": "M14",
   "system": "Metric",
   "socket": "21 mm",
   "across_flats_in": 0.8268,
   "across_flats_mm": 21,
   "legacy_note": "DIN 931 uses 22 mm"
  },
  {
   "fastener": "M16",
   "system": "Metric",
   "socket": "24 mm",
   "across_flats_in": 0.9449,
   "across_flats_mm": 24,
   "legacy_note": ""
  },
  {
   "fastener": "M18",
   "system": "Metric",
   "socket": "27 mm",
   "across_flats_in": 1.063,
   "across_flats_mm": 27,
   "legacy_note": ""
  },
  {
   "fastener": "M20",
   "system": "Metric",
   "socket": "30 mm",
   "across_flats_in": 1.1811,
   "across_flats_mm": 30,
   "legacy_note": ""
  },
  {
   "fastener": "M22",
   "system": "Metric",
   "socket": "34 mm",
   "across_flats_in": 1.3386,
   "across_flats_mm": 34,
   "legacy_note": "DIN 931 uses 32 mm"
  },
  {
   "fastener": "M24",
   "system": "Metric",
   "socket": "36 mm",
   "across_flats_in": 1.4173,
   "across_flats_mm": 36,
   "legacy_note": ""
  },
  {
   "fastener": "M27",
   "system": "Metric",
   "socket": "41 mm",
   "across_flats_in": 1.6142,
   "across_flats_mm": 41,
   "legacy_note": ""
  },
  {
   "fastener": "M30",
   "system": "Metric",
   "socket": "46 mm",
   "across_flats_in": 1.811,
   "across_flats_mm": 46,
   "legacy_note": ""
  }
 ]
}