Tapping Sizes and Clearance Holes

Drill size and clearance hole recommendations  

All dimensions are recommendations only and are shown in mm.

Metric threads
ThreadDrill size for tapping standard metric threadsDrill size for tapping fine metric threadsClearance hole
M10.75-1.2
M1.20.95-1.4
M1.41.1-1.6
M1.61.5-1.8
M1.81.4-2
M21.6-2.4
M2.21.7-2.8
M2.52-2.9
M32.5-3.4
M3.52.9-3.9
M43.3-4.5
M54.2-5.5
M65-6.6
M86.879
M108.58.811
M1210.210.813.5
M141212.515.5
M161414.517.5
M1815.516.520
M2017.518.522
M2219.520.524
M24212226
M27242530
M3026.52833

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.