Material Thickness Versus Punch Diameter

The Cleveland Punch and Die tip for the day deals with the relation of material thickness to punch diameter. The thickness of material being punched plays a significant role in punch and die life. This is especially true when punching holes where the diameter of the punch is close to, or greater than the thickness of material. During the era of the mechanical punching machine, the general rule of thumb that has been practiced is to not punch material thicker than the diameter of the punch.

Since the beginning of the hydraulic punching machine, the shock once associated with mechanical punching is minimal. Although, in certain applications, extreme pressures may be generated when holes are punched in material that is thicker than the diameter of the punch. The pressure and wear on the punch and die is greater during this type of punching and will consequently shorten tooling life. While we don't suggest engaging in this type of punching, we do know that there are applications where it can not be avoided. In these circumstances, we would recommend plenty of lubrication (Punch Easy) and extra clearance to provide some relief on the pressure exerted to the punch.