Punch Marks

Punch marks are almost always circular in shape and, therefore, the area of the punch mark can be determined using the calculation r2 (where 3.142). The radius of the punch mark can be measured using a magnifier as can the separation of two punch marks – measured centre to centre. The depth measurement would require the use of a depth probe. While the depth of a punch mark is limited to 0.040 inches (1.02 mm) within the Rules, it is highly unlikely that this measurement would ever be queried “in the field”.