Hex cap screws and heavy hex screws, inch 7/8 to 1-1/2 (ASME B18.2.1): across flats F, head height H, thread length LT — dimension sheet Source: Xem Studio, https://xemstudio.com/objects/hex-cap-screws-heavy-hex-screws-inch-7-8-to-1-1-2/ (sheet CC BY 4.0) Basis: ASME B18.2.1 tables as printed by M.E. Campbell (cap screws), Boltport (cap screws and heavy hex screws) and Torqbolt (heavy hex values); inches, max / min as printed; 12 envelope files Catalog version: 2026-10-20 Overall (mm): length 44.0, width 38.1, height 126.3 - Two head styles share these sizes. A hex cap screw (ASME B18.2.1) has the regular head: 1-5/16 in across flats at 7/8, 1-1/2 at 1, 1-11/16 at 1-1/8, 1-7/8 at 1-1/4, 2-1/16 at 1-3/8, 2-1/4 at 1-1/2. A heavy hex screw has the larger head: F max 1.438, 1.625, 1.812, 2.000, 2.188, 2.375 in. Head height H is the same for both (H max .563, .627, .718, .813, .878, .974 in). The existing page hex-bolts-inch covers 1/4-20 to 3/4-10; this page continues the cap screws and adds the heavy hex style. - Two independent printings agree on every cap-screw value (M.E. Campbell and Boltport) and on every heavy hex value (Boltport and Torqbolt's table, whose heading says 'hex screws' but whose F, G and H are the heavy hex column). Body diameter E min differs by style: .8660 (cap) against .852 (heavy) at 7/8. - Thread length LT: M.E. Campbell and Boltport print two columns, for screw lengths 6 in and shorter and over 6 in (the Boltport page does not label the two columns; the reading is the same as M.E. Campbell's for the cap screws). Torqbolt prints a single LT min per size, and it equals the longer-screw column (2.250 at 7/8 to 3.500 at 1-1/2). Cap and heavy hex LT are identical at each size. M.E. Campbell marks LT as a reference value. - J min is the minimum wrenching height; only Boltport prints it (cap screws only: .378 / .416 / .461 / .530 / .569 / .640 in). Boltport also prints runout and a Y value whose column headings were not clear, so they are not used. - Threads: UNC 9, 8, 7, 7, 6, 6 and UNF 14, 12, 12, 12, 12, 12 threads per inch for 7/8 to 1-1/2 (see threaded-rod-inch-unc-unf-sizes). Class 2A threads. The files draw the thread as a plain cylinder at the major diameter. - Files: 12 envelopes, one per size and style. The head is a hexagonal prism at F max and H max, the shank a plain cylinder at E max, 4 in under the head. 4 in is an example length of ours; ASME B18.2.1 lists many standard lengths. No washer face, head chamfer, fillet or thread is drawn, because those are not in the tables read. Not covered: the plain hex bolt (ASME B18.2.1 hex bolt) at 7/8 and up, which has its own head heights (not read here). style size (in) UNC / UNF TPI E body dia max / min F across flats max / min G across corners max / min H head height max / min J wrenching height min (cap only) LT thread length, L ≤ 6 in LT thread length, L > 6 in file: F max / H max (mm) hex cap screw 7/8 9 / 14 .8750 / .8660 1.312 / 1.285 1.516 / 1.465 .563 / .531 .378 2.000 2.250 33.32 / 14.3 hex cap screw 1 8 / 12 1.0000 / .9900 1.500 / 1.469 1.732 / 1.675 .627 / .591 .416 2.250 2.500 38.1 / 15.93 hex cap screw 1-1/8 7 / 12 1.1250 / 1.1140 1.688 / 1.631 1.949 / 1.859 .718 / .658 .461 2.500 2.750 42.88 / 18.24 hex cap screw 1-1/4 7 / 12 1.2500 / 1.2390 1.875 / 1.812 2.165 / 2.066 .813 / .749 .530 2.750 3.000 47.62 / 20.65 hex cap screw 1-3/8 6 / 12 1.3750 / 1.3630 2.062 / 1.994 2.382 / 2.273 .878 / .810 .569 3.000 3.250 52.37 / 22.3 hex cap screw 1-1/2 6 / 12 1.5000 / 1.4880 2.250 / 2.175 2.598 / 2.480 .974 / .902 .640 3.250 3.500 57.15 / 24.74 heavy hex screw 7/8 9 / 14 .8750 / .852 1.438 / 1.394 1.660 / 1.589 .563 / .531 – 2.000 2.250 36.53 / 14.3 heavy hex screw 1 8 / 12 1.0000 / .976 1.625 / 1.575 1.876 / 1.796 .627 / .591 – 2.250 2.500 41.27 / 15.93 heavy hex screw 1-1/8 7 / 12 1.1250 / 1.098 1.812 / 1.756 2.093 / 2.002 .718 / .658 – 2.500 2.750 46.02 / 18.24 heavy hex screw 1-1/4 7 / 12 1.2500 / 1.223 2.000 / 1.938 2.309 / 2.209 .813 / .749 – 2.750 3.000 50.8 / 20.65 heavy hex screw 1-3/8 6 / 12 1.3750 / 1.345 2.188 / 2.119 2.526 / 2.416 .878 / .810 – 3.000 3.250 55.58 / 22.3 heavy hex screw 1-1/2 6 / 12 1.5000 / 1.470 2.375 / 2.300 2.742 / 2.622 .974 / .902 – 3.250 3.500 60.32 / 24.74 Files elsewhere (not hosted by Xem Studio; license as stated by the publisher): - M.E. Campbell (distributor): Hex Head Cap Screws spec (ASME B18.2.1): E, F, G, H, LT for lengths <= 6 in and > 6 in — web — Publisher's page; dimensions are facts — https://www.mecampbell.com/media/pdf/Hex_Head_Cap_Screws_spec.pdf - Boltport (mirror host as read): ASME B18.2.1 hex cap screws: E, F, G, H, J, LT, Y, runout, 1/4 to 3 in — web — Publisher's page; dimensions are facts — https://www.boltport.com.ferrobend.com/standards/asme-b18.2.1/hex-cap-screws - Boltport (mirror host as read): ASME B18.2.1 heavy hex screws: E, F, G, H, LT, 3/8 to 6 in — web — Publisher's page; dimensions are facts — https://www.boltport.com.ferrobend.com/standards/asme-b18.2.1/heavy-hex-screws - Torqbolt: ASME B18.2.1 screws table (heading says hex screws; the values are the heavy hex column): E, F basic / max / min, G, H basic / max / min, LT min — web — Publisher's page; dimensions are facts — https://torqbolt.com/asme-b18-2-1-heavy-hex-screws-dimensions-standards-specifications - ASME: ASME B18.2.1 Square, hex, heavy hex, askew head bolts and hex, heavy hex, hex flange, lobed head and lag screws (inch) — web — ASME; dimensions are facts — https://www.asme.org/codes-standards/find-codes-standards/b18-2-1-square-hex-heavy-hex-askew-head-bolts-hex-heavy-hex-hex-flange-lobed-head-lag-screws-inch-series - Torqbolt: ASME B18.31.3 threaded rods: nominal diameters and UNC / UNF threads per inch, #4 to 5 in — web — Publisher's page; dimensions are facts — https://torqbolt.com/asme-b18-31-3-threaded-rods-dimensions-standards-specifications Free files (CC BY 4.0, Xem Studio; STEP + STL, 12 parts): https://xemstudio.com/files/hardware/hex-cap-screws-heavy-hex-screws-inch-7-8-to-1-1-2/index.json API: https://xemstudio.com/api/geometry?object=hex-cap-screws-heavy-hex-screws-inch-7-8-to-1-1-2