Tap and Clearance Reference Sheet
We use this as a reference tool that covers standard dimensions for many of the threads and clearance holes that we commonly use within our shop. We find it handy and hope you do as well.
 
Tap drills are assuming a 75% thread, 0.015" of head clearance for counterbores and countersinks, listed center drills offer a minimum and maximum range for tapping, and all dimensions are given in inches.
MECHANICAL CONCEPTS, INC
Established in 1979
Design & Fabrication of Custom Engineered Machinery
 
We use this as a reference tool that covers standard dimensions for many of the threads and clearance holes that we commonly use within our shop. We find it handy and hope you do as well.  
 
Tap drills are assuming a 75% thread, 0.015" of head clearance for counterbores and countersinks, listed center drills offer a minimum and maximum range for tapping, and all dimensions are given in inches.  
 
Center Drill: 
Countersink:
Inch: 10-24 
#3 - #4.5 
82 Deg
.411 
.385 
.121 
.190 
.201 
.112 
.205 
.375 
.312 
.190 
.1495 
[7] 
[25] 
Metric 
Inch
Design & Fabrication of Custom Engineered Machinery
 
Established in 1979 
MECHANICAL CONCEPTS, INC