CLEARANCE HOLES FOR METRIC FASTENERS


"Clearance holes for metric fasteners" calculator was developed to calculate the recommended clearance hole sizes from M1.6 through M64 for bolts, screws and studs in three classes of clearance using close-, normal- and loose-fit category. The recommended metric drill bit size for each class of clearance hole is shown in calculation results. The calculator also shows nearest substitute inch drill bit size for metric fasteners.

This calculator was developed by using the charts which are given in the ASME B18.2.8-1999 - " Clearance holes for bolts, screws and studs" standard.

Metric Clearance Hole Calculator:


INPUT PARAMETERS
Nominal Screw Size
Fit Class

 


Clearance Hole
RESULTS
Parameter Value
Nominal Screw Size --- mm
Fit Class --- --
Nominal Metric Drill Size --- mm
Nearest Inch Drill Size --- in
Minimum Hole Diameter --- mm
Maximum Hole Diameter ---

Definitions:

Clearance hole: A hole on a part where threaded section of a bolt can pass.

Drill bit: A cutting tool used in drilling machines to drill a hole.

Supplements:

Link Usage
Metric clearance hole chart Tabulated form of the metric clearance hole calculator.

Reference:

  • Oberg, E. , Jones ,F.D. , Horton H.L. , Ryffel H.H., (2016) . Machinery's Handbook . 30th edition.  Industrial Press Inc.
  • Oberg, E. , Jones ,F.D. , Horton H.L. , Ryffel H.H., (2012) . Machinery's Handbook . 29th edition.  Industrial Press Inc. , pp 1609 - 1612
  • ASME B18.2.8-1999, Clearance holes for bolts, screws and studs