Enter the diameter of the fastener (in) and the diameter of the fastener head (in) into the Calculator. The calculator will evaluate the Clearance Hole. 

Clearance Hole Formula

CH = (DF + DH) / 2

Variables:

  • CH is the Clearance Hole (in)
  • DF is the diameter of the fastener (in)
  • DH is the diameter of the fastener head (in)

To calculate the Clearance Hole, add the diameter of the fastener and the diameter of the head, then divide by 2.

How to Calculate Clearance Hole?

The following steps outline how to calculate the Clearance Hole.

  1. First, determine the diameter of the fastener (in). 
  2. Next, determine the diameter of the fastener head (in). 
  3. Next, gather the formula from above = CH = (DF + DH) / 2.
  4. Finally, calculate the Clearance Hole.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

diameter of the fastener (in) = 1.25

diameter of the fastener head (in) = 0.4