PUNCH CLEARANCE CHART FOR MILD STEEL - PDF format
This chart will provide you with the proper punch clearances for different thicknesses of mild steel. Too little clearance will produce a double-shear and will shorten the life span of a sharp tool. Too much punch clearance will produce burrs, deformation of the punched hole and will increase wear on the punch tooling.
Punch Clearances for Mild Steel - PDF format