Threaded rod, inch: #4 to 4 in, UNC and UNF threads per inch, major diameter in inches and mm, standard lengths — dimension sheet Source: Xem Studio, https://xemstudio.com/objects/threaded-rod-inch-unc-unf-sizes/ (sheet CC BY 4.0) Basis: ASME B18.31.3 as summarised by Torqbolt (sizes, TPI) and fasten.it (lengths); numbers only Catalog version: 2026-10-20 Sizes: see table below - Inch threaded rod (studding, all-thread; ASME B18.31.3) is cut from stock in the UNC (coarse) or UNF (fine) series. Sizes and threads per inch are from Torqbolt's B18.31.3 summary. Its 7/16 row prints 0.4370 in; the fraction 7/16 is 0.4375 in and that is shown. The second source's table (fasten.it) lists the UNC and UNF numbers one row out of step for the fractional sizes (its UNC column reads 18 for 1/4 where Torqbolt has 20, and 16 for 5/16 where Torqbolt has 18), so its TPI numbers are not used. - Nominal diameter is the major diameter of the thread; the major diameter limits that the standard prints were not on a page that could be read. No file is added: a rod is a plain cylinder (Xem draws threads as plain cylinders at the major diameter) and carries no more than the number. - Lengths: ASME B18.31.3 says rods are normally produced in, but not limited to, 3 ft, 6 ft, 10 ft and 12 ft; length tolerance is ±1/2 in for nominal lengths of 6 ft and longer and ±1/4 in under 6 ft (fasten.it's B18.31.3 page). Cut-to-length rods are common. - Metric rod (DIN 976, M3 to M12) is on the threaded-rod-metric-din-976 page. Left out: thread class limits, minor and pitch diameters, mechanical grades (A307, B7, 18-8) and the UNS-size 1-14 for 1 in UNF. size nominal major diameter (in) major diameter (mm, computed) UNC UNC pitch (mm, computed 25.4 ÷ TPI) UNF #4 0.1120 2.84 4-40 0.635 4-48 #5 0.1250 3.17 5-40 0.635 5-44 #6 0.1380 3.51 6-32 0.794 6-40 #8 0.1640 4.17 8-32 0.794 8-36 #10 0.1900 4.83 10-24 1.058 10-32 #12 0.2160 5.49 12-24 1.058 12-28 1/4 0.2500 6.35 1/4-20 1.270 1/4-28 5/16 0.3125 7.94 5/16-18 1.411 5/16-24 3/8 0.3750 9.52 3/8-16 1.587 3/8-24 7/16 0.4375 11.11 7/16-14 1.814 7/16-20 1/2 0.5000 12.70 1/2-13 1.954 1/2-20 9/16 0.5625 14.29 9/16-12 2.117 9/16-18 5/8 0.6250 15.88 5/8-11 2.309 5/8-18 3/4 0.7500 19.05 3/4-10 2.540 3/4-16 7/8 0.8750 22.22 7/8-9 2.822 7/8-14 1 1.0000 25.40 1-8 3.175 1-12 (the source also prints 1-14 UNS) 1-1/8 1.1250 28.57 1-1/8-7 3.629 1-12 1-1/4 1.2500 31.75 1-1/4-7 3.629 1-12 1-3/8 1.3750 34.92 1-3/8-6 4.233 1-12 1-1/2 1.5000 38.10 1-1/2-6 4.233 1-12 1-3/4 1.7500 44.45 1-3/4-5 5.080 - 2 2.0000 50.80 2-4.5 5.644 - 2-1/4 2.2500 57.15 2-1/4-4.5 5.644 - 2-1/2 2.5000 63.50 2-1/2-4 6.350 - 2-3/4 2.7500 69.85 2-3/4-4 6.350 - 3 3.0000 76.20 3-4 6.350 - 3-1/4 3.2500 82.55 3-1/4-4 6.350 - 3-1/2 3.5000 88.90 3-1/2-4 6.350 - 3-3/4 3.7500 95.25 3-3/4-4 6.350 - 4 4.0000 101.60 4-4 6.350 - Files elsewhere (not hosted by Xem Studio; license as stated by the publisher): - 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 - fasten.it: ASME B18.31.3 Standard dimensions for threaded rods, inch series: normal lengths 3, 6, 10, 12 ft and length tolerance — web — Publisher's page; dimensions are facts — https://fasten.it/norms/norm/asme_b18.31.3 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=threaded-rod-inch-unc-unf-sizes