--- title: "Unified inch thread chart — tap drills and clearance holes" description: "Every unified inch thread size with its tap drill, clearance hole, hex size and torque. 40 sizes, coarse and fine." url: https://atoneplace.net/fastener/unified/ site: "At One Place" --- # Unified inch thread chart 40 unified inch thread sizes, with the drill to tap each one and the hole to clear it. | Thread | Pitch | Tap drill | Clearance | Hex | Torque | | --- | --- | --- | --- | --- | --- | | #0-80 UNF | 80 tpi | 3/64" | 1.78 mm | — | — | | #1-72 UNF | 72 tpi | #53 | 2.06 mm | — | — | | #1-64 UNC | 64 tpi | #53 | 2.06 mm | — | — | | #2-64 UNF | 64 tpi | #50 | 2.44 mm | — | — | | #2-56 UNC | 56 tpi | #50 | 2.44 mm | — | — | | #3-48 UNC | 48 tpi | #47 | 2.79 mm | — | — | | #4-48 UNF | 48 tpi | #42 | 3.26 mm | 6.35 mm | — | | #4-40 UNC | 40 tpi | #43 | 3.26 mm | 6.35 mm | — | | #5-40 UNC | 40 tpi | #38 | 3.45 mm | 7.94 mm | — | | #6-40 UNF | 40 tpi | #33 | 3.8 mm | 7.94 mm | — | | #6-32 UNC | 32 tpi | #36 | 3.8 mm | 7.94 mm | — | | #8-32 UNC | 32 tpi | #29 | 4.5 mm | 8.73 mm | — | | #10-32 UNF | 32 tpi | #21 | 5.11 mm | 9.52 mm | — | | #10-24 UNC | 24 tpi | #25 | 5.11 mm | 9.52 mm | — | | #12-24 UNC | 24 tpi | #16 | 5.79 mm | 11.11 mm | — | | 1/4"-32 UNEF | 32 tpi | 7/32" | 6.76 mm | 11.11 mm | — | | 1/4"-28 UNF | 28 tpi | #3 | 6.76 mm | 11.11 mm | 10.5–14.5 N·m | | 1/4"-20 UNC | 20 tpi | #7 | 6.76 mm | 11.11 mm | 9–12.5 N·m | | 5/16"-24 UNF | 24 tpi | I | 8.43 mm | 12.7 mm | 21–29 N·m | | 5/16"-18 UNC | 18 tpi | F | 8.43 mm | 12.7 mm | 19–26 N·m | | 3/8"-32 UNEF | 32 tpi | 11/32" | 10.08 mm | 14.29 mm | — | | 3/8"-24 UNF | 24 tpi | Q | 10.08 mm | 14.29 mm | 38–52 N·m | | 3/8"-16 UNC | 16 tpi | 5/16" | 10.08 mm | 14.29 mm | 34–46 N·m | | 7/16"-20 UNF | 20 tpi | 25/64" | 11.91 mm | 15.88 mm | 60–82 N·m | | 7/16"-14 UNC | 14 tpi | U | 11.91 mm | 15.88 mm | 54–73 N·m | | 1/2"-28 UNEF | 28 tpi | 15/32" | 13.49 mm | 19.05 mm | — | | 1/2"-20 UNF | 20 tpi | 29/64" | 13.49 mm | 19.05 mm | 92–126 N·m | | 1/2"-13 UNC | 13 tpi | 27/64" | 13.49 mm | 19.05 mm | 82–112 N·m | | 9/16"-18 UNF | 18 tpi | 33/64" | 15.08 mm | 20.64 mm | 132–180 N·m | | 9/16"-12 UNC | 12 tpi | 31/64" | 15.08 mm | 20.64 mm | 118–162 N·m | | 5/8"-27 UNS | 27 tpi | 15 mm | 16.67 mm | 23.81 mm | — | | 5/8"-18 UNF | 18 tpi | 37/64" | 16.67 mm | 23.81 mm | 185–253 N·m | | 5/8"-11 UNC | 11 tpi | 17/32" | 16.67 mm | 23.81 mm | 163–223 N·m | | 3/4"-20 UNEF | 20 tpi | 45/64" | 19.84 mm | 28.57 mm | — | | 3/4"-16 UNF | 16 tpi | 11/16" | 19.84 mm | 28.57 mm | 320–440 N·m | | 3/4"-10 UNC | 10 tpi | 21/32" | 19.84 mm | 28.57 mm | 290–395 N·m | | 7/8"-14 UNF | 14 tpi | 13/16" | 23.02 mm | 33.34 mm | 515–700 N·m | | 7/8"-9 UNC | 9 tpi | 49/64" | 23.02 mm | 33.34 mm | 465–640 N·m | | 1"-12 UNF | 12 tpi | 59/64" | 26.19 mm | 38.1 mm | 765–1050 N·m | | 1"-8 UNC | 8 tpi | 7/8" | 26.19 mm | 38.1 mm | 700–960 N·m | > Plain steel property class 8.8 or SAE grade 5, dry threads, tightened to about 65% of yield. Lubricated threads reach the same preload at 20-30% less torque. Where the manufacturer publishes a figure — spark plugs, wheel nuts, cylinder heads — use theirs. - [#0-80 UNF](https://atoneplace.net/fastener/number-0-80/) — 3/64" tap drill - [#1-72 UNF](https://atoneplace.net/fastener/number-1-72/) — #53 tap drill - [#1-64 UNC](https://atoneplace.net/fastener/number-1-64/) — #53 tap drill - [#2-64 UNF](https://atoneplace.net/fastener/number-2-64/) — #50 tap drill - [#2-56 UNC](https://atoneplace.net/fastener/number-2-56/) — #50 tap drill - [#3-48 UNC](https://atoneplace.net/fastener/number-3-48/) — #47 tap drill - [#4-48 UNF](https://atoneplace.net/fastener/number-4-48/) — #42 tap drill - [#4-40 UNC](https://atoneplace.net/fastener/number-4-40/) — #43 tap drill - [#5-40 UNC](https://atoneplace.net/fastener/number-5-40/) — #38 tap drill - [#6-40 UNF](https://atoneplace.net/fastener/number-6-40/) — #33 tap drill - [#6-32 UNC](https://atoneplace.net/fastener/number-6-32/) — #36 tap drill - [#8-32 UNC](https://atoneplace.net/fastener/number-8-32/) — #29 tap drill - [#10-32 UNF](https://atoneplace.net/fastener/number-10-32/) — #21 tap drill - [#10-24 UNC](https://atoneplace.net/fastener/number-10-24/) — #25 tap drill - [#12-24 UNC](https://atoneplace.net/fastener/number-12-24/) — #16 tap drill - [1/4"-32 UNEF](https://atoneplace.net/fastener/quarter-32/) — 7/32" tap drill - [1/4"-28 UNF](https://atoneplace.net/fastener/quarter-28/) — #3 tap drill - [1/4"-20 UNC](https://atoneplace.net/fastener/quarter-20/) — #7 tap drill - [5/16"-24 UNF](https://atoneplace.net/fastener/five-sixteenths-24/) — I tap drill - [5/16"-18 UNC](https://atoneplace.net/fastener/five-sixteenths-18/) — F tap drill - [3/8"-32 UNEF](https://atoneplace.net/fastener/three-eighths-32/) — 11/32" tap drill - [3/8"-24 UNF](https://atoneplace.net/fastener/three-eighths-24/) — Q tap drill - [3/8"-16 UNC](https://atoneplace.net/fastener/three-eighths-16/) — 5/16" tap drill - [7/16"-20 UNF](https://atoneplace.net/fastener/seven-sixteenths-20/) — 25/64" tap drill - [7/16"-14 UNC](https://atoneplace.net/fastener/seven-sixteenths-14/) — U tap drill - [1/2"-28 UNEF](https://atoneplace.net/fastener/half-28/) — 15/32" tap drill - [1/2"-20 UNF](https://atoneplace.net/fastener/half-20/) — 29/64" tap drill - [1/2"-13 UNC](https://atoneplace.net/fastener/half-13/) — 27/64" tap drill - [9/16"-18 UNF](https://atoneplace.net/fastener/nine-sixteenths-18/) — 33/64" tap drill - [9/16"-12 UNC](https://atoneplace.net/fastener/nine-sixteenths-12/) — 31/64" tap drill - [5/8"-27 UNS](https://atoneplace.net/fastener/five-eighths-27/) — 15 mm tap drill - [5/8"-18 UNF](https://atoneplace.net/fastener/five-eighths-18/) — 37/64" tap drill - [5/8"-11 UNC](https://atoneplace.net/fastener/five-eighths-11/) — 17/32" tap drill - [3/4"-20 UNEF](https://atoneplace.net/fastener/three-quarters-20/) — 45/64" tap drill - [3/4"-16 UNF](https://atoneplace.net/fastener/three-quarters-16/) — 11/16" tap drill - [3/4"-10 UNC](https://atoneplace.net/fastener/three-quarters-10/) — 21/32" tap drill - [7/8"-14 UNF](https://atoneplace.net/fastener/seven-eighths-14/) — 13/16" tap drill - [7/8"-9 UNC](https://atoneplace.net/fastener/seven-eighths-9/) — 49/64" tap drill - [1"-12 UNF](https://atoneplace.net/fastener/one-inch-12/) — 59/64" tap drill - [1"-8 UNC](https://atoneplace.net/fastener/one-inch-8/) — 7/8" tap drill ## Sources - Official vendor product documentation — At One Place (/about/) - Typical range compiled from manufacturer specifications — At One Place (/about/)