Shoulder screws ASME B18.3 (inch): shoulder Ø 1/4 to 3/4 in, thread, head size, hex key, thread length — dimension sheet Source: Xem Studio, https://xemstudio.com/objects/shoulder-screws-asme-b18-3/ (sheet CC BY 4.0) Basis: ASME B18.3-2003 shoulder screw tables as published by AFT Fasteners and Holo-Krome; McMaster-Carr linked for CAD Catalog version: 2026-10-20 Sizes: see table below - ASME B18.3 socket shoulder screws: the shoulder diameter is the size name (1/4 in shoulder = #10-24 thread, 5/16 = 1/4-20, 3/8 = 5/16-18, 1/2 = 3/8-16, 5/8 = 1/2-13, 3/4 = 5/8-11). The shoulder is ground slightly under nominal (for 1/4 in: .2480 / .2460 max / min; 5/16: .3105 / .3085; 3/8: .3730 / .3710; 1/2: .4980 / .4960; 5/8: .6230 / .6210; 3/4: .7480 / .7450 or .7460), so a bore for it is nominal plus your clearance. - Two independent tables (AFT Fasteners' B18.3-2003 sheet and Holo-Krome's shoulder screw sheet) agree on shoulder D max / min, head diameter A, head height H, hex key J, key engagement T and thread length E for all six sizes. Only the .7450 vs .7460 minimum for the 3/4 in shoulder differs. Other columns (neck diameters, fillet radii, chamfer C) are printed in both but their column assignment was ambiguous in extraction, so they are not used. - Shoulder length is the dimension you select; the two sheets above do not print a length range, so no standard lengths are claimed here. Shoulder length tolerance: −.02 in up to 3/8 in shoulder, −.03 in above (AFT). McMaster-Carr carries these in inch sizes (shoulder length in 1/8 in or 1/4 in steps by size); the category links are below. - Files: six solids, one per size, with an example 1 in (25.4 mm) shoulder length. Thread is drawn as a plain cylinder at the nominal major diameter (from the thread designation; #10 = .190 in) over the thread length E; head diameter and height are the maxima; socket depth is the minimum key engagement T. No chamfers, fillets or thread neck. Left out: larger shoulders (1 in and up), which neither sheet's text carried legibly. - Metric ISO 7379 shoulder screws are on the companion page. shoulder Ø D (nominal) thread head Ø A (max), in (mm) head height H (max), in (mm) hex key J, in (mm) key engagement T (min), in thread length E, in (mm) 1/4 (6.35 mm) #10-24 0.375 (9.52) 0.188 (4.78) 1/8 (3.17) 0.094 0.375 (9.52) 5/16 (7.94 mm) 1/4-20 0.438 (11.13) 0.219 (5.56) 5/32 (3.97) 0.117 0.438 (11.13) 3/8 (9.52 mm) 5/16-18 0.562 (14.27) 0.250 (6.35) 3/16 (4.76) 0.141 0.500 (12.70) 1/2 (12.70 mm) 3/8-16 0.750 (19.05) 0.312 (7.92) 1/4 (6.35) 0.188 0.625 (15.88) 5/8 (15.88 mm) 1/2-13 0.875 (22.22) 0.375 (9.52) 5/16 (7.94) 0.234 0.750 (19.05) 3/4 (19.05 mm) 5/8-11 1.000 (25.40) 0.500 (12.70) 3/8 (9.52) 0.281 0.875 (22.22) Files elsewhere (not hosted by Xem Studio; license as stated by the publisher): - AFT Fasteners: Socket shoulder screw dimensions (alloy steel), ASME B18.3-2003 — web — Publisher's page; dimensions are facts — https://aftfasteners.com/socket-shoulder-screws-dimensions-mechanical-properties - Holo-Krome (Global Industrial PDF): Socket shoulder screw dimensions (D, A, H, J, T, E) — web — Publisher's page; dimensions are facts — https://www.globalindustrial.com/site/images/holokrome/socketshoulder.pdf - McMaster-Carr: Steel shoulder screws (inch and metric) (free STEP/IGES per part, for your own design use; no redistribution) — STEP, IGES, PDF — McMaster-Carr site terms: personal design use, no redistribution [verify license at link] — https://www.mcmaster.com/products/steel-shoulder-screws/ - McMaster-Carr: Shoulder screws, ISO 7379 filter (free STEP/IGES per part, for your own design use; no redistribution) — STEP, IGES, PDF — McMaster-Carr site terms: personal design use, no redistribution [verify license at link] — https://www.mcmaster.com/products/shoulder-screws/specifications-met~iso-7379 Free files (CC BY 4.0, Xem Studio; STEP + STL, 6 parts): https://xemstudio.com/files/hardware/shoulder-screws-asme-b18-3/index.json API: https://xemstudio.com/api/geometry?object=shoulder-screws-asme-b18-3