Metric clearance hole calculator for bolts and screws to calculate the recommended clearance hole sizes from M1.6 through M64 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 with nearest substitute inch drill bit size.
Metric clearance hole calculator is according to ASME B18.2.8 standard.
Clearance hole: A hole on a part where threaded section of a bolt can pass.