99 sizes

Unified (UNC / UNF / UNEF) threads

Tap the size you need for its full dimensions, tap drill, clearance hole, torque estimate and wrench sizes.

UNC - Unified coarse UNF - Unified fine UNEF - Unified extra-fine UN - Unified constant-pitch

27 sizes

UNC - Unified coarse

#1-64 UNCTap #53Ø 1.854 mm · pitch 0.397 mm #2-56 UNCTap #50Ø 2.184 mm · pitch 0.454 mm #3-48 UNCTap #47Ø 2.515 mm · pitch 0.529 mm #4-40 UNCTap #43Ø 2.845 mm · pitch 0.635 mm #5-40 UNCTap #38Ø 3.175 mm · pitch 0.635 mm #6-32 UNCTap #36Ø 3.505 mm · pitch 0.794 mm #8-32 UNCTap #29Ø 4.166 mm · pitch 0.794 mm #10-24 UNCTap #25Ø 4.826 mm · pitch 1.058 mm #12-24 UNCTap #16Ø 5.486 mm · pitch 1.058 mm 1/4-20 UNCTap #7Ø 6.35 mm · pitch 1.27 mm 5/16-18 UNCTap FØ 7.938 mm · pitch 1.411 mm 3/8-16 UNCTap 5/16"Ø 9.525 mm · pitch 1.588 mm 7/16-14 UNCTap UØ 11.112 mm · pitch 1.814 mm 1/2-13 UNCTap 27/64"Ø 12.7 mm · pitch 1.954 mm 9/16-12 UNCTap 31/64"Ø 14.288 mm · pitch 2.117 mm 5/8-11 UNCTap 17/32"Ø 15.875 mm · pitch 2.309 mm 3/4-10 UNCTap 21/32"Ø 19.05 mm · pitch 2.54 mm 7/8-9 UNCTap 49/64"Ø 22.225 mm · pitch 2.822 mm 1-8 UNCTap 7/8"Ø 25.4 mm · pitch 3.175 mm 1-1/8-7 UNCTap 63/64"Ø 28.575 mm · pitch 3.629 mm 1-1/4-7 UNCTap 1"Ø 31.75 mm · pitch 3.629 mm 1-3/8-6 UNCTap 1"Ø 34.925 mm · pitch 4.233 mm 1-1/2-6 UNCTap 1"Ø 38.1 mm · pitch 4.233 mm 1-3/4-5 UNCTap 1"Ø 44.45 mm · pitch 5.08 mm 2-4.5 UNCTap 1"Ø 50.8 mm · pitch 5.644 mm 2-1/4-4.5 UNCTap 1"Ø 57.15 mm · pitch 5.644 mm 2-1/2-4 UNCTap 1"Ø 63.5 mm · pitch 6.35 mm

24 sizes

UNF - Unified fine

#0-80 UNFTap 3/64"Ø 1.524 mm · pitch 0.318 mm #1-72 UNFTap #53Ø 1.854 mm · pitch 0.353 mm #2-64 UNFTap #50Ø 2.184 mm · pitch 0.397 mm #3-56 UNFTap #45Ø 2.515 mm · pitch 0.454 mm #4-48 UNFTap #42Ø 2.845 mm · pitch 0.529 mm #5-44 UNFTap #37Ø 3.175 mm · pitch 0.577 mm #6-40 UNFTap #33Ø 3.505 mm · pitch 0.635 mm #8-36 UNFTap #29Ø 4.166 mm · pitch 0.706 mm #10-32 UNFTap #21Ø 4.826 mm · pitch 0.794 mm #12-28 UNFTap #14Ø 5.486 mm · pitch 0.907 mm 1/4-28 UNFTap #3Ø 6.35 mm · pitch 0.907 mm 5/16-24 UNFTap IØ 7.938 mm · pitch 1.058 mm 3/8-24 UNFTap QØ 9.525 mm · pitch 1.058 mm 7/16-20 UNFTap 25/64"Ø 11.112 mm · pitch 1.27 mm 1/2-20 UNFTap 29/64"Ø 12.7 mm · pitch 1.27 mm 9/16-18 UNFTap 33/64"Ø 14.288 mm · pitch 1.411 mm 5/8-18 UNFTap 37/64"Ø 15.875 mm · pitch 1.411 mm 3/4-16 UNFTap 11/16"Ø 19.05 mm · pitch 1.588 mm 7/8-14 UNFTap 13/16"Ø 22.225 mm · pitch 1.814 mm 1-12 UNFTap 59/64"Ø 25.4 mm · pitch 2.117 mm 1-1/8-12 UNFTap 1"Ø 28.575 mm · pitch 2.117 mm 1-1/4-12 UNFTap 1"Ø 31.75 mm · pitch 2.117 mm 1-3/8-12 UNFTap 1"Ø 34.925 mm · pitch 2.117 mm 1-1/2-12 UNFTap 1"Ø 38.1 mm · pitch 2.117 mm

15 sizes

UNEF - Unified extra-fine

#12-32 UNEFTap #13Ø 5.486 mm · pitch 0.794 mm 1/4-32 UNEFTap 7/32"Ø 6.35 mm · pitch 0.794 mm 5/16-32 UNEFTap 9/32"Ø 7.938 mm · pitch 0.794 mm 3/8-32 UNEFTap 11/32"Ø 9.525 mm · pitch 0.794 mm 7/16-28 UNEFTap YØ 11.112 mm · pitch 0.907 mm 1/2-28 UNEFTap 15/32"Ø 12.7 mm · pitch 0.907 mm 9/16-24 UNEFTap 33/64"Ø 14.288 mm · pitch 1.058 mm 5/8-24 UNEFTap 37/64"Ø 15.875 mm · pitch 1.058 mm 3/4-20 UNEFTap 45/64"Ø 19.05 mm · pitch 1.27 mm 7/8-20 UNEFTap 53/64"Ø 22.225 mm · pitch 1.27 mm 1-20 UNEFTap 61/64"Ø 25.4 mm · pitch 1.27 mm 1-1/8-18 UNEFTap 1"Ø 28.575 mm · pitch 1.411 mm 1-1/4-18 UNEFTap 1"Ø 31.75 mm · pitch 1.411 mm 1-3/8-18 UNEFTap 1"Ø 34.925 mm · pitch 1.411 mm 1-1/2-18 UNEFTap 1"Ø 38.1 mm · pitch 1.411 mm

33 sizes

UN - Unified constant-pitch

9/16-20 UNTap 33/64"Ø 14.288 mm · pitch 1.27 mm 5/8-20 UNTap 37/64"Ø 15.875 mm · pitch 1.27 mm 5/8-16 UNTap 9/16"Ø 15.875 mm · pitch 1.588 mm 3/4-12 UNTap 43/64"Ø 19.05 mm · pitch 2.117 mm 7/8-16 UNTap 13/16"Ø 22.225 mm · pitch 1.588 mm 7/8-12 UNTap 51/64"Ø 22.225 mm · pitch 2.117 mm 1-16 UNTap 15/16"Ø 25.4 mm · pitch 1.588 mm 1-1/8-20 UNTap 1"Ø 28.575 mm · pitch 1.27 mm 1-1/8-16 UNTap 1"Ø 28.575 mm · pitch 1.588 mm 1-1/8-8 UNTap 1"Ø 28.575 mm · pitch 3.175 mm 1-1/4-20 UNTap 1"Ø 31.75 mm · pitch 1.27 mm 1-1/4-16 UNTap 1"Ø 31.75 mm · pitch 1.588 mm 1-1/4-8 UNTap 1"Ø 31.75 mm · pitch 3.175 mm 1-3/8-20 UNTap 1"Ø 34.925 mm · pitch 1.27 mm 1-3/8-16 UNTap 1"Ø 34.925 mm · pitch 1.588 mm 1-3/8-8 UNTap 1"Ø 34.925 mm · pitch 3.175 mm 1-1/2-20 UNTap 1"Ø 38.1 mm · pitch 1.27 mm 1-1/2-16 UNTap 1"Ø 38.1 mm · pitch 1.588 mm 1-1/2-8 UNTap 1"Ø 38.1 mm · pitch 3.175 mm 1-3/4-20 UNTap 1"Ø 44.45 mm · pitch 1.27 mm 1-3/4-16 UNTap 1"Ø 44.45 mm · pitch 1.588 mm 1-3/4-12 UNTap 1"Ø 44.45 mm · pitch 2.117 mm 1-3/4-8 UNTap 1"Ø 44.45 mm · pitch 3.175 mm 2-20 UNTap 1"Ø 50.8 mm · pitch 1.27 mm 2-16 UNTap 1"Ø 50.8 mm · pitch 1.588 mm 2-12 UNTap 1"Ø 50.8 mm · pitch 2.117 mm 2-8 UNTap 1"Ø 50.8 mm · pitch 3.175 mm 2-1/4-16 UNTap 1"Ø 57.15 mm · pitch 1.588 mm 2-1/4-12 UNTap 1"Ø 57.15 mm · pitch 2.117 mm 2-1/4-8 UNTap 1"Ø 57.15 mm · pitch 3.175 mm 2-1/2-16 UNTap 1"Ø 63.5 mm · pitch 1.588 mm 2-1/2-12 UNTap 1"Ø 63.5 mm · pitch 2.117 mm 2-1/2-8 UNTap 1"Ø 63.5 mm · pitch 3.175 mm

Frequently asked questions

How do I read a 1/2-13 UNC callout?

1/2 is the nominal major diameter in inches and 13 is the number of threads per inch. UNC marks it as a Unified coarse thread, the default inch series for general fastening in this diameter.

What is the difference between UNC and UNF?

UNC is Unified coarse, the default inch series for general fastening. UNF is Unified fine: fine pitches have a larger stress area than coarse at the same diameter and suit thin walls, fine adjustment and vibration-sensitive joints.