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)

sizes

69 in table

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.

Sheet metal screw pilot holes: drill size and hole diameter for… size chart

Mating features

Drawn at the exact size. Open press, slide, run and socket features by your process's clearance (tolerances by process); leave designed gaps and clamp fits as drawn.

Where the files are

Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.

Xem scan

File coming

No downloadable true-size file yet: the published figures do not fix the whole shape, and Xem never guesses a number. A measured scan is planned; request it and it moves up.

Plain text: sheet.txt · JSON: /api/geometry?object=sheet-metal-screw-pilot-holes

Fits with

Free

Self-tapping (sheet metal) screws: ISO 7049 pan head ST2.2–ST6.3 and ASME B18.6.4 Type AB thread #2 to 3/820 sizes★ sheetFree

Thread-forming screws for plastic (EJOT PT type): screw hole diameter by plastic, M2.2–M4, boss hole rule, K sizes20 sizes★ sheetFree

Helical wire thread inserts (Helicoil style, DIN 8140): M3–M16 drill size, tapped hole, insert length 1D–3D12 sizes★ sheetFree

Imperial machine screws: #4-40, #6-32, #8-32, 1/4-204 sizes★ 18 filesFree

Rivet nuts (blind threaded inserts), flat head: hole size, grip range, body and flange dimensions, M3–M12 and #6-32 to 3/8-16131.7×32.1×3.0 mm★ 1 fileFree

PEM self-clinching nuts (S, CLS, CLSS): hole size, minimum edge distance, nut diameter and height, M2–M12 and #2-56 to 3/8-24 + hole gauges98.2×25.0×3.0 mm★ 2 files