Thread Conversion Table

Due to the differences in thread angles and pitches, the thread sizes shown below are not directly interchangeable with each other. This table is only to help find a nearest equivalent sized fastener.

 

Metric Coarse Metric Fine BSF/BSW UNC UNF
M2 x 0.4 - - 1-64 1-72
M2.5 x 0.45 - - 3-48 3-56
M3 x 0.5 - - 4-40 4-48
M3.5 x 0.6 - - 6-32 6-40
M4 x 0.7 - - 8-32 8-36
M5 x 0.8 - - 10-24 10-32
M6 x 1 M6 x 0.75 1/4" 1/4-20 1/4-28
M8 x 1.25 M8 x 1 5/16" 5/16-18 5/16-24
M10 x 1.5 M10 x 1.25 3/8" 3/8-16 3/8-24
M12 x 1.75 M12 x 1.25 1/2" 1/2-13 1/2-20
M14 x 2 M14 x 1.5 9/16" 9/16-12 9/16-18
M16 x 2 M16 x 1.5 5/8" 5/8-11 5/8-18
M20 x 2.5 M20 x 1.5 3/4" 3/4-10 3/4-16
M24 x 3 M24 x 2 1" 1-8 1-12
M30 x 3.5 M30 x 2 1-1/8" 1 1/4-7 1 1/8-12
M36 x 4 M36 x 3 1-3/8" 1 1/2-6 1 1/4-12


Note: Due to the fact that fastening applications differ greatly, the above information is for guidance only and is correct to the best of our knowledge. The customer must satisfy themselves with the performance of the fastener and validity of the data. TR Fastenings will not be held responsible for any failure that may occur from the use of this information.