Self-tapping (sheet metal) screws: ISO 7049 pan head ST2.2–ST6.3 and ASME B18.6.4 Type AB thread #2 to 3/8 — dimension sheet Source: Xem Studio, https://xemstudio.com/objects/self-tapping-screws-iso-7049-pan-head/ (sheet CC BY 4.0) Basis: fasteners.eu's ISO 7049 table (pan head, form C and F) and two copies of the Type AB thread table (HB Bolt, citing ASME B18.6.4-1998, and a maker sheet citing B18.6.3-2013); numbers only Catalog version: 2026-10-20 Sizes: see table below - ISO 7049 rows are mm, pan head tapping screws with cross recess (types H and Z), forms C (conical point) and F (flat point): thread pitch P, head diameter dk (nominal = max, with min), head height k (nominal = max, with min), r max (under-head radius), rf (head crown radius, 'approx.') and the cross-recess number. ST3.9 is in brackets in the standard (non-preferred), as on the page. The page also tabulates recess depths, the dimension m (approx.) and the minimum / maximum screw length by form, which are not repeated here. Pitch 'a max' equals the pitch in every column. The ST thread itself (ISO 1478) major and minor diameters were not in the source read. - Type AB rows are inches: nominal size #2 to 3/8, basic screw diameter D, threads per inch, major diameter max / min, minor diameter max / min. HB Bolt cites ASME B18.6.4-1998 and the second sheet cites B18.6.3-2013; the numbers are identical on both. The second sheet labels the two columns after the diameters as 'min practical screw length' for 90° (flat-under-head) and countersunk heads and the last as minimum torsional strength in lb-in for steel screws; HB Bolt's headers were jumbled, so the labels come from that second sheet. Length tolerance (both): ±0.03 in up to 1 in, ±0.05 in over 1 in. - Pan head dimensions for the inch Type AB / A screws (B18.6.4 pan head tables) were not in the sources read; none is given. The ST-size to Type AB size correspondence (for example ST4.2 versus #8) is not printed by the sources read and is not claimed. Pilot holes for these screws: sheet-metal-screw-pilot-holes; plastics: plastic-thread-forming-screw-holes. - No file: the pan head crown shape is given by rf 'approx.' and the recess profile is not drawn here, and the thread is a plain cylinder; the brief rule against plain shapes applies. McMaster-Carr sells sheet metal screws with per-part STEP; the category is linked, not copied. standard size pitch / TPI head dia dk max / min (mm) head height k max / min (mm) r max, rf (mm) | major, minor (in) recess min practical length (in) min torsional strength ISO 7049 pan head (mm) ST2.2 0.8 mm 4.2 / 3.9 1.8 / 1.55 r max 0.3; rf ≈ 3.4 cross recess No. 1 — — ISO 7049 pan head (mm) ST2.9 1.1 mm 5.6 / 5.3 2.2 / 1.95 r max 0.4; rf ≈ 4.4 cross recess No. 1 — — ISO 7049 pan head (mm) ST3.5 1.3 mm 6.9 / 6.54 2.6 / 2.35 r max 0.5; rf ≈ 5.4 cross recess No. 2 — — ISO 7049 pan head (mm) (ST3.9) 1.3 mm 7.5 / 7.14 2.8 / 2.55 r max 0.5; rf ≈ 5.8 cross recess No. 2 — — ISO 7049 pan head (mm) ST4.2 1.4 mm 8.2 / 7.84 3.05 / 2.75 r max 0.6; rf ≈ 6.2 cross recess No. 2 — — ISO 7049 pan head (mm) ST4.8 1.6 mm 9.5 / 9.14 3.55 / 3.25 r max 0.7; rf ≈ 7.2 cross recess No. 2 — — ISO 7049 pan head (mm) ST5.5 1.8 mm 10.8 / 10.37 3.95 / 3.65 r max 0.8; rf ≈ 8.2 cross recess No. 3 — — ISO 7049 pan head (mm) ST6.3 1.8 mm 12.5 / 12.07 4.55 / 4.25 r max 0.9; rf ≈ 9.5 cross recess No. 3 — — ASME B18.6.4 Type AB thread (in) #2 32 TPI; basic .0860 — — major .088 / .082; minor .064 / .060 — 3/16 (90° heads); 7/32 (csk heads) 4 lb-in (steel) ASME B18.6.4 Type AB thread (in) #3 28 TPI; basic .0990 — — major .101 / .095; minor .075 / .071 — 3/16 (90° heads); 1/4 (csk heads) 9 lb-in (steel) ASME B18.6.4 Type AB thread (in) #4 24 TPI; basic .1120 — — major .114 / .108; minor .086 / .082 — 7/32 (90° heads); 9/32 (csk heads) 13 lb-in (steel) ASME B18.6.4 Type AB thread (in) #5 20 TPI; basic .1250 — — major .130 / .123; minor .094 / .090 — 1/4 (90° heads); 5/16 (csk heads) 18 lb-in (steel) ASME B18.6.4 Type AB thread (in) #6 20 TPI; basic .1380 — — major .139 / .132; minor .104 / .099 — 9/32 (90° heads); 11/32 (csk heads) 24 lb-in (steel) ASME B18.6.4 Type AB thread (in) #7 19 TPI; basic .1510 — — major .154 / .147; minor .115 / .109 — 5/16 (90° heads); 3/8 (csk heads) 30 lb-in (steel) ASME B18.6.4 Type AB thread (in) #8 18 TPI; basic .1640 — — major .166 / .159; minor .122 / .116 — 5/16 (90° heads); 3/8 (csk heads) 39 lb-in (steel) ASME B18.6.4 Type AB thread (in) #10 16 TPI; basic .1900 — — major .189 / .182; minor .141 / .135 — 3/8 (90° heads); 7/16 (csk heads) 56 lb-in (steel) ASME B18.6.4 Type AB thread (in) #12 14 TPI; basic .2160 — — major .215 / .208; minor .164 / .157 — 7/16 (90° heads); 21/32 (csk heads) 88 lb-in (steel) ASME B18.6.4 Type AB thread (in) 1/4 14 TPI; basic .2500 — — major .246 / .237; minor .192 / .185 — 1/2 (90° heads); 19/32 (csk heads) 142 lb-in (steel) ASME B18.6.4 Type AB thread (in) 5/16 12 TPI; basic .3125 — — major .315 / .306; minor .244 / .236 — 5/8 (90° heads); 3/4 (csk heads) 290 lb-in (steel) ASME B18.6.4 Type AB thread (in) 3/8 12 TPI; basic .3750 — — major .380 / .371; minor .309 / .299 — 3/4 (90° heads); 29/32 (csk heads) 590 lb-in (steel) Files elsewhere (not hosted by Xem Studio; license as stated by the publisher): - fasteners.eu: ISO 7049 pan head tapping screws with cross recess H and Z, form C and F: P, a, dk, k, r, rf, recess, ST2.2 to ST6.3 and lengths — web — Reference page; numbers only — https://www.fasteners.eu/standards/ISO/7049/ - HB Bolt: Type AB tapping screw thread (ASME B18.6.4-1998): basic diameter, threads per inch, major and minor diameter max / min, #2 to 3/8 — web — Maker cut sheet; numbers only. Headers jumbled in the text read — https://www.hbbolt.com/_Product_Cut_Sheets/TypeABPointInfo.pdf - Cold-forged fastener maker sheet (hosted on a Shopify CDN, maker not named in the text read): Threads for self-tapping screws, Type AB: same table with labelled columns including minimum practical screw length (90° and countersunk heads) and minimum torsional strength; cites ASME B18.6.3-2013 — web — Maker datasheet; numbers only — https://cdn2.shopify.com/s/files/1/0056/7856/3437/files/SttypeAB.pdf No true-size file yet: the published figures do not fix the whole shape; a measured scan is planned. API: https://xemstudio.com/api/geometry?object=self-tapping-screws-iso-7049-pan-head