{
 "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": "sheet-metal-screw-pilot-holes",
 "name": "Sheet metal screw pilot holes: drill size and hole diameter for Types AB, A and 1/23/F, by sheet thickness (#2 to 1/2)",
 "kind": "standard",
 "category": "Hardware",
 "group": "Fasteners",
 "year": null,
 "question": "What drill size and hole diameter does a #8 sheet metal screw need in 18 gauge or 0.036 in steel?",
 "tags": [
  "sheet metal screw pilot hole",
  "pilot hole sheet metal",
  "type ab pilot hole",
  "type a screw hole",
  "self tapping screw drill size",
  "drill size for sheet metal screw",
  "tapping screw hole",
  "fastener",
  "tool"
 ],
 "aliases": [
  "#8 sheet metal screw pilot hole",
  "#10 sheet metal screw drill size",
  "what size drill bit for #6 sheet metal screw",
  "#8 self tapping screw hole size",
  "sheet metal screw pilot hole 18 gauge",
  "type ab screw hole size",
  "#6 sheet metal screw drill bit",
  "1/4 self tapping screw pilot hole",
  "#12 sheet metal screw drill size",
  "sheet metal screw hole diameter chart",
  "pierced vs drilled hole screw",
  "#4 sheet metal screw drill size"
 ],
 "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/sheet-metal-screw-pilot-holes/",
 "sheet_txt": "https://xemstudio.com/objects/sheet-metal-screw-pilot-holes/sheet.txt",
 "sheet": {
  "basis": "AFT Fasteners' self-tapping screw hole-size tables (test-plate gage and thickness, drill, hole diameter) and Engineers Edge's Type A table by metal thickness (pierced / extruded versus drilled / clean punched); numbers only",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "Inch tables. AFT gives, per screw size and thread (size-TPI), the test-plate gage and its thickness max / min, the drill size (number, letter, fraction or mm as printed) and the resulting hole diameter, for Types AB / B / 25 (thread forming), Type A (spaced thread, no plate thickness given) and Types 1 / 23 / F (thread cutting). Engineers Edge gives Type A holes by metal thickness: the hole diameter for pierced or extruded holes and for drilled or clean-punched holes, with the drill size, for #4 to #14 in steel, stainless steel, Monel, brass and aluminum. AFT states holes can be drilled, core drilled, punched, pierced or extruded and that burrs should be removed if they interfere; hole size is the nominal hole diameter, not a tolerance. Engineers Edge prints no units; the values read as inches.",
   "Oddities kept as printed, not corrected: AFT's Types AB row '4.24' (printed with a dot; the thread is 4-24); the 8-18 row gives gage 14 with thickness .1270 / .1230 in (1/8 in), unlike the gage 14 rows above it (.0770 / .0730 in); the 3-48 row of the thread-cutting table prints .0920 for both max and min. AFT's Type A table lists sizes 5 to 24 (24-9 for the 11/32 in drill) with threads different from the AB table (for example 6-18 versus 6-20), because the type has a different thread.",
   "Not on this page: pilot holes for plastics and wood (see plastic-thread-forming-screw-holes and wood-screws-flat-head-inch), the AFT Type U drive-screw and High-Low tables (read but not tabulated), and metric ST sizes (the sources read give no hole table for them). The two sources do not overlap in the same screw type and thickness for every size: for example #8 Type A is 0.136 in (drill #29) in AFT's Type A table, Engineers Edge prints 0.125 in (1/8 in drill) for drilled holes in 0.018 to 0.036 in steel and 0.136 in for pierced holes, so check the table for your thickness.",
   "No file: these are hole sizes (numbers). McMaster-Carr sells sheet metal screws with per-part STEP; its category is linked on self-tapping-screws-iso-7049-pan-head."
  ],
  "table": {
   "columns": [
    "source / screw type",
    "size (size-TPI, or # for Engineers Edge)",
    "test plate or metal thickness",
    "drill size",
    "hole diameter, drilled / clean punched (in)",
    "hole diameter, pierced or extruded (in)"
   ],
   "rows": [
    [
     "AFT, Types AB / B / 25",
     "2-32",
     "gage 18, .0500 / .0460 in",
     "48",
     ".0760",
     "—"
    ],
    [
     "AFT, Types AB / B / 25",
     "3-28",
     "gage 18, .0500 / .0460 in",
     "46",
     ".0810",
     "—"
    ],
    [
     "AFT, Types AB / B / 25",
     "4-24 (printed 4.24)",
     "gage 18, .0500 / .0460 in",
     "44",
     ".0860",
     "—"
    ],
    [
     "AFT, Types AB / B / 25",
     "5-20",
     "gage 18, .0500 / .0460 in",
     "36",
     ".1065",
     "—"
    ],
    [
     "AFT, Types AB / B / 25",
     "6-20",
     "gage 14, .0770 / .0730 in",
     "32",
     ".1160",
     "—"
    ],
    [
     "AFT, Types AB / B / 25",
     "7-19",
     "gage 14, .0770 / .0730 in",
     "30",
     ".1285",
     "—"
    ],
    [
     "AFT, Types AB / B / 25",
     "8-18",
     "gage 14, .1270 / .1230 in",
     "29",
     ".1360",
     "—"
    ],
    [
     "AFT, Types AB / B / 25",
     "10-16",
     "gage 1/8, .1270 / .1230 in",
     "21",
     ".1590",
     "—"
    ],
    [
     "AFT, Types AB / B / 25",
     "12-14",
     "gage 1/8, .1270 / .1230 in",
     "3/16",
     ".1875",
     "—"
    ],
    [
     "AFT, Types AB / B / 25",
     "1/4-14",
     "gage 3/16, .1905 / .1845 in",
     "5.5 mm",
     ".2165",
     "—"
    ],
    [
     "AFT, Types AB / B / 25",
     "5/16-12",
     "gage 3/16, .1905 / .1845 in",
     "I",
     ".2720",
     "—"
    ],
    [
     "AFT, Types AB / B / 25",
     "3/8-12",
     "gage 3/16, .1905 / .1845 in",
     "21/64",
     ".3281",
     "—"
    ],
    [
     "AFT, Type A",
     "5-20",
     "—",
     "#36",
     "0.1065",
     "—"
    ],
    [
     "AFT, Type A",
     "6-18",
     "—",
     "#32",
     "0.1160",
     "—"
    ],
    [
     "AFT, Type A",
     "7-16",
     "—",
     "#30",
     "0.1285",
     "—"
    ],
    [
     "AFT, Type A",
     "8-15",
     "—",
     "#29",
     "0.1360",
     "—"
    ],
    [
     "AFT, Type A",
     "9-14",
     "—",
     "#26",
     "0.1470",
     "—"
    ],
    [
     "AFT, Type A",
     "10-12",
     "—",
     "#21",
     "0.1590",
     "—"
    ],
    [
     "AFT, Type A",
     "12-11",
     "—",
     "3/16",
     "0.1875",
     "—"
    ],
    [
     "AFT, Type A",
     "14-10",
     "—",
     "5.5 mm",
     "0.2165",
     "—"
    ],
    [
     "AFT, Type A",
     "20-9",
     "—",
     "L",
     "0.2900",
     "—"
    ],
    [
     "AFT, Type A",
     "24-9",
     "—",
     "11/32",
     "0.3438",
     "—"
    ],
    [
     "AFT, Types 1 / 23 / F (thread cutting)",
     "2-56",
     "gage 18, .0800 / .0760 in",
     "49",
     "0.0730",
     "—"
    ],
    [
     "AFT, Types 1 / 23 / F (thread cutting)",
     "3-48",
     "gage 18, .0920 / .0920 in",
     "46",
     "0.0810",
     "—"
    ],
    [
     "AFT, Types 1 / 23 / F (thread cutting)",
     "4-40",
     "gage 18, .1110 / .1070 in",
     "41",
     "0.0960",
     "—"
    ],
    [
     "AFT, Types 1 / 23 / F (thread cutting)",
     "5-40",
     "gage 18, .1110 / .1070 in",
     "37",
     "0.1010",
     "—"
    ],
    [
     "AFT, Types 1 / 23 / F (thread cutting)",
     "6-32",
     "gage 14, .1425 / .1385 in",
     "31",
     "0.1200",
     "—"
    ],
    [
     "AFT, Types 1 / 23 / F (thread cutting)",
     "8-32",
     "gage 14, .1905 / .1845 in",
     "26",
     "0.1470",
     "—"
    ],
    [
     "AFT, Types 1 / 23 / F (thread cutting)",
     "10-24",
     "gage 1/8, .1905 / .1845 in",
     "17",
     "0.1730",
     "—"
    ],
    [
     "AFT, Types 1 / 23 / F (thread cutting)",
     "10-32",
     "gage 1/8, .1905 / .1845 in",
     "16",
     "0.1770",
     "—"
    ],
    [
     "AFT, Types 1 / 23 / F (thread cutting)",
     "12-24",
     "gage 1/8, .1905 / .1845 in",
     "8",
     "0.1990",
     "—"
    ],
    [
     "AFT, Types 1 / 23 / F (thread cutting)",
     "1/4-20",
     "gage 3/16, .2530 / .2470 in",
     "1",
     "0.2280",
     "—"
    ],
    [
     "AFT, Types 1 / 23 / F (thread cutting)",
     "5/16-18",
     "gage 3/16, .3155 / .3095 in",
     "L",
     "0.2900",
     "—"
    ],
    [
     "AFT, Types 1 / 23 / F (thread cutting)",
     "3/8-16",
     "gage 3/16, .3780 / .3720 in",
     "T",
     "0.3580",
     "—"
    ],
    [
     "AFT, Types 1 / 23 / F (thread cutting)",
     "1/2-13",
     "gage 3/16, .471 / .443 in",
     "29/64",
     "0.4531",
     "—"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#4",
     "0.015 in",
     "44",
     "0.086",
     "—"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#4",
     "0.018 in",
     "44",
     "0.086",
     "—"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#4",
     "0.024 in",
     "42",
     "0.094",
     "0.098"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#4",
     "0.030 in",
     "42",
     "0.094",
     "0.098"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#4",
     "0.036 in",
     "40",
     "0.098",
     "0.098"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#6",
     "0.015 in",
     "37",
     "0.104",
     "—"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#6",
     "0.018 in",
     "37",
     "0.104",
     "—"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#6",
     "0.024 in",
     "37",
     "0.104",
     "0.111"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#6",
     "0.030 in",
     "37",
     "0.104",
     "0.111"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#6",
     "0.036 in",
     "36",
     "0.106",
     "0.111"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#7",
     "0.015 in",
     "32",
     "0.116",
     "—"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#7",
     "0.018 in",
     "32",
     "0.116",
     "—"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#7",
     "0.024 in",
     "32",
     "0.116",
     "0.120"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#7",
     "0.030 in",
     "32",
     "0.116",
     "0.120"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#7",
     "0.036 in",
     "32",
     "0.116",
     "0.120"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#7",
     "0.048 in",
     "31",
     "0.120",
     "0.120"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#8",
     "0.018 in",
     "1/8",
     "0.125",
     "—"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#8",
     "0.024 in",
     "1/8",
     "0.125",
     "0.136"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#8",
     "0.030 in",
     "1/8",
     "0.125",
     "0.136"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#8",
     "0.036 in",
     "1/8",
     "0.125",
     "0.136"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#8",
     "0.048 in",
     "30",
     "0.128",
     "0.136"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#10",
     "0.018 in",
     "29",
     "0.136",
     "—"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#10",
     "0.024 in",
     "29",
     "0.136",
     "0.157"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#10",
     "0.030 in",
     "29",
     "0.136",
     "0.157"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#10",
     "0.036 in",
     "29",
     "0.136",
     "0.157"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#10",
     "0.048 in",
     "25",
     "0.149",
     "0.157"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#12",
     "0.024 in",
     "20",
     "0.161",
     "—"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#12",
     "0.030 in",
     "20",
     "0.161",
     "0.185"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#12",
     "0.036 in",
     "20",
     "0.161",
     "0.185"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#12",
     "0.048 in",
     "20",
     "0.161",
     "0.185"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#14",
     "0.024 in",
     "13",
     "0.185",
     "—"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#14",
     "0.030 in",
     "12",
     "0.189",
     "0.209"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#14",
     "0.036 in",
     "11",
     "0.191",
     "0.209"
    ],
    [
     "Engineers Edge, Type A by metal thickness",
     "#14",
     "0.048 in",
     "9",
     "0.196",
     "0.209"
    ]
   ]
  }
 },
 "sheet_text": "Sheet metal screw pilot holes: drill size and hole diameter for Types AB, A and 1/23/F, by sheet thickness (#2 to 1/2) — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/sheet-metal-screw-pilot-holes/  (sheet CC BY 4.0)\nBasis: AFT Fasteners' self-tapping screw hole-size tables (test-plate gage and thickness, drill, hole diameter) and Engineers Edge's Type A table by metal thickness (pierced / extruded versus drilled / clean punched); numbers only\nCatalog version: 2026-10-20\n\nSizes: see table below\n- Inch tables. AFT gives, per screw size and thread (size-TPI), the test-plate gage and its thickness max / min, the drill size (number, letter, fraction or mm as printed) and the resulting hole diameter, for Types AB / B / 25 (thread forming), Type A (spaced thread, no plate thickness given) and Types 1 / 23 / F (thread cutting). Engineers Edge gives Type A holes by metal thickness: the hole diameter for pierced or extruded holes and for drilled or clean-punched holes, with the drill size, for #4 to #14 in steel, stainless steel, Monel, brass and aluminum. AFT states holes can be drilled, core drilled, punched, pierced or extruded and that burrs should be removed if they interfere; hole size is the nominal hole diameter, not a tolerance. Engineers Edge prints no units; the values read as inches.\n- Oddities kept as printed, not corrected: AFT's Types AB row '4.24' (printed with a dot; the thread is 4-24); the 8-18 row gives gage 14 with thickness .1270 / .1230 in (1/8 in), unlike the gage 14 rows above it (.0770 / .0730 in); the 3-48 row of the thread-cutting table prints .0920 for both max and min. AFT's Type A table lists sizes 5 to 24 (24-9 for the 11/32 in drill) with threads different from the AB table (for example 6-18 versus 6-20), because the type has a different thread.\n- Not on this page: pilot holes for plastics and wood (see plastic-thread-forming-screw-holes and wood-screws-flat-head-inch), the AFT Type U drive-screw and High-Low tables (read but not tabulated), and metric ST sizes (the sources read give no hole table for them). The two sources do not overlap in the same screw type and thickness for every size: for example #8 Type A is 0.136 in (drill #29) in AFT's Type A table, Engineers Edge prints 0.125 in (1/8 in drill) for drilled holes in 0.018 to 0.036 in steel and 0.136 in for pierced holes, so check the table for your thickness.\n- No file: these are hole sizes (numbers). McMaster-Carr sells sheet metal screws with per-part STEP; its category is linked on self-tapping-screws-iso-7049-pan-head.\n\nsource / screw type  size (size-TPI, or # for Engineers Edge)  test plate or metal thickness  drill size  hole diameter, drilled / clean punched (in)  hole diameter, pierced or extruded (in)\nAFT, Types AB / B / 25  2-32  gage 18, .0500 / .0460 in  48  .0760  —\nAFT, Types AB / B / 25  3-28  gage 18, .0500 / .0460 in  46  .0810  —\nAFT, Types AB / B / 25  4-24 (printed 4.24)  gage 18, .0500 / .0460 in  44  .0860  —\nAFT, Types AB / B / 25  5-20  gage 18, .0500 / .0460 in  36  .1065  —\nAFT, Types AB / B / 25  6-20  gage 14, .0770 / .0730 in  32  .1160  —\nAFT, Types AB / B / 25  7-19  gage 14, .0770 / .0730 in  30  .1285  —\nAFT, Types AB / B / 25  8-18  gage 14, .1270 / .1230 in  29  .1360  —\nAFT, Types AB / B / 25  10-16  gage 1/8, .1270 / .1230 in  21  .1590  —\nAFT, Types AB / B / 25  12-14  gage 1/8, .1270 / .1230 in  3/16  .1875  —\nAFT, Types AB / B / 25  1/4-14  gage 3/16, .1905 / .1845 in  5.5 mm  .2165  —\nAFT, Types AB / B / 25  5/16-12  gage 3/16, .1905 / .1845 in  I  .2720  —\nAFT, Types AB / B / 25  3/8-12  gage 3/16, .1905 / .1845 in  21/64  .3281  —\nAFT, Type A  5-20  —  #36  0.1065  —\nAFT, Type A  6-18  —  #32  0.1160  —\nAFT, Type A  7-16  —  #30  0.1285  —\nAFT, Type A  8-15  —  #29  0.1360  —\nAFT, Type A  9-14  —  #26  0.1470  —\nAFT, Type A  10-12  —  #21  0.1590  —\nAFT, Type A  12-11  —  3/16  0.1875  —\nAFT, Type A  14-10  —  5.5 mm  0.2165  —\nAFT, Type A  20-9  —  L  0.2900  —\nAFT, Type A  24-9  —  11/32  0.3438  —\nAFT, Types 1 / 23 / F (thread cutting)  2-56  gage 18, .0800 / .0760 in  49  0.0730  —\nAFT, Types 1 / 23 / F (thread cutting)  3-48  gage 18, .0920 / .0920 in  46  0.0810  —\nAFT, Types 1 / 23 / F (thread cutting)  4-40  gage 18, .1110 / .1070 in  41  0.0960  —\nAFT, Types 1 / 23 / F (thread cutting)  5-40  gage 18, .1110 / .1070 in  37  0.1010  —\nAFT, Types 1 / 23 / F (thread cutting)  6-32  gage 14, .1425 / .1385 in  31  0.1200  —\nAFT, Types 1 / 23 / F (thread cutting)  8-32  gage 14, .1905 / .1845 in  26  0.1470  —\nAFT, Types 1 / 23 / F (thread cutting)  10-24  gage 1/8, .1905 / .1845 in  17  0.1730  —\nAFT, Types 1 / 23 / F (thread cutting)  10-32  gage 1/8, .1905 / .1845 in  16  0.1770  —\nAFT, Types 1 / 23 / F (thread cutting)  12-24  gage 1/8, .1905 / .1845 in  8  0.1990  —\nAFT, Types 1 / 23 / F (thread cutting)  1/4-20  gage 3/16, .2530 / .2470 in  1  0.2280  —\nAFT, Types 1 / 23 / F (thread cutting)  5/16-18  gage 3/16, .3155 / .3095 in  L  0.2900  —\nAFT, Types 1 / 23 / F (thread cutting)  3/8-16  gage 3/16, .3780 / .3720 in  T  0.3580  —\nAFT, Types 1 / 23 / F (thread cutting)  1/2-13  gage 3/16, .471 / .443 in  29/64  0.4531  —\nEngineers Edge, Type A by metal thickness  #4  0.015 in  44  0.086  —\nEngineers Edge, Type A by metal thickness  #4  0.018 in  44  0.086  —\nEngineers Edge, Type A by metal thickness  #4  0.024 in  42  0.094  0.098\nEngineers Edge, Type A by metal thickness  #4  0.030 in  42  0.094  0.098\nEngineers Edge, Type A by metal thickness  #4  0.036 in  40  0.098  0.098\nEngineers Edge, Type A by metal thickness  #6  0.015 in  37  0.104  —\nEngineers Edge, Type A by metal thickness  #6  0.018 in  37  0.104  —\nEngineers Edge, Type A by metal thickness  #6  0.024 in  37  0.104  0.111\nEngineers Edge, Type A by metal thickness  #6  0.030 in  37  0.104  0.111\nEngineers Edge, Type A by metal thickness  #6  0.036 in  36  0.106  0.111\nEngineers Edge, Type A by metal thickness  #7  0.015 in  32  0.116  —\nEngineers Edge, Type A by metal thickness  #7  0.018 in  32  0.116  —\nEngineers Edge, Type A by metal thickness  #7  0.024 in  32  0.116  0.120\nEngineers Edge, Type A by metal thickness  #7  0.030 in  32  0.116  0.120\nEngineers Edge, Type A by metal thickness  #7  0.036 in  32  0.116  0.120\nEngineers Edge, Type A by metal thickness  #7  0.048 in  31  0.120  0.120\nEngineers Edge, Type A by metal thickness  #8  0.018 in  1/8  0.125  —\nEngineers Edge, Type A by metal thickness  #8  0.024 in  1/8  0.125  0.136\nEngineers Edge, Type A by metal thickness  #8  0.030 in  1/8  0.125  0.136\nEngineers Edge, Type A by metal thickness  #8  0.036 in  1/8  0.125  0.136\nEngineers Edge, Type A by metal thickness  #8  0.048 in  30  0.128  0.136\nEngineers Edge, Type A by metal thickness  #10  0.018 in  29  0.136  —\nEngineers Edge, Type A by metal thickness  #10  0.024 in  29  0.136  0.157\nEngineers Edge, Type A by metal thickness  #10  0.030 in  29  0.136  0.157\nEngineers Edge, Type A by metal thickness  #10  0.036 in  29  0.136  0.157\nEngineers Edge, Type A by metal thickness  #10  0.048 in  25  0.149  0.157\nEngineers Edge, Type A by metal thickness  #12  0.024 in  20  0.161  —\nEngineers Edge, Type A by metal thickness  #12  0.030 in  20  0.161  0.185\nEngineers Edge, Type A by metal thickness  #12  0.036 in  20  0.161  0.185\nEngineers Edge, Type A by metal thickness  #12  0.048 in  20  0.161  0.185\nEngineers Edge, Type A by metal thickness  #14  0.024 in  13  0.185  —\nEngineers Edge, Type A by metal thickness  #14  0.030 in  12  0.189  0.209\nEngineers Edge, Type A by metal thickness  #14  0.036 in  11  0.191  0.209\nEngineers Edge, Type A by metal thickness  #14  0.048 in  9  0.196  0.209\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- AFT Fasteners: Self-tapping screws hole size data, Types AB / B / 25, A, 1 / 23 / F, U and High-Low: test-plate gauge and thickness, drill size, hole diameter — web — Publisher's page; dimensions are facts — https://www.aftfasteners.com/self-tapping-screws-hole-size-data-for-types-a-ab-b-25-1-23-f-u-high-low-technical-information\n- Engineers Edge: Pilot hole sizes for Type A steel sheet metal screws by metal thickness: pierced or extruded versus drilled or clean punched, drill size, #4 to #14 — web — Publisher's page; dimensions are facts — https://engineersedge.com/hardware/pilot_hole_sizes_for_steel_sheet_metal_15670.htm\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=sheet-metal-screw-pilot-holes\n",
 "sources": [
  {
   "publisher": "AFT Fasteners",
   "title": "Self-tapping screws hole size data, Types AB / B / 25, A, 1 / 23 / F, U and High-Low: test-plate gauge and thickness, drill size, hole diameter",
   "url": "https://www.aftfasteners.com/self-tapping-screws-hole-size-data-for-types-a-ab-b-25-1-23-f-u-high-low-technical-information",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Engineers Edge",
   "title": "Pilot hole sizes for Type A steel sheet metal screws by metal thickness: pierced or extruded versus drilled or clean punched, drill size, #4 to #14",
   "url": "https://engineersedge.com/hardware/pilot_hole_sizes_for_steel_sheet_metal_15670.htm",
   "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": [
  "self-tapping-screws-iso-7049-pan-head",
  "plastic-thread-forming-screw-holes",
  "helical-thread-inserts-din-8140",
  "imperial-machine-screws",
  "rivet-nuts-flat-head",
  "pem-self-clinching-nuts-s-cls",
  "tek-self-drilling-screw-drill-points",
  "drill-size-index-number-letter-fraction"
 ],
 "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": "pilot hole",
   "exact": "Type AB: 8-18 drill 29 (.1360 in), 10-16 drill 21 (.1590 in), 1/4-14 drill 5.5 mm (.2165 in); Type A by thickness in the table",
   "mates": "Type AB, A or 1 / 23 / F screw of the listed size",
   "fit": "designed",
   "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 drill for a #8 sheet metal screw in 0.030 in steel?",
   "a": "Engineers Edge (Type A): 1/8 in drill, 0.125 in hole for a drilled or clean-punched hole, 0.136 in for a pierced or extruded hole. AFT's Type A table prints 0.136 in (drill #29) without a thickness."
  },
  {
   "q": "What hole for a #10 Type AB screw?",
   "a": "AFT: size 10-16, drill 21, hole 0.1590 in, in a 1/8 in test plate (0.1270 / 0.1230 in)."
  },
  {
   "q": "What drill for a 1/4-20 thread-cutting screw?",
   "a": "AFT Types 1 / 23 / F: drill 1 (0.2280 in) in a 3/16 in test plate."
  }
 ],
 "files_license": null,
 "offers": [],
 "markdown": "https://xemstudio.com/objects/sheet-metal-screw-pilot-holes/index.md"
}