FAQs

This is the dimension added to the round punch diameter or shapedpunch dimensions. Die clearance is determined by the type and thickness of the material you are punching. 

For stainless steel, the die clearance is 25% of the material thickness. For mild steel, the die clearance is 20% of the material thickness. For aluminum, copper or brass, the die clearance is 15% of the material thickness.

For example, to calculate the die clearance for 1/8” mild steel, multiply .125 x 20%. The die clearance is .025”.

Calculate the required tonnage per hole with this formula:

3.1416 x Diameter of Hole x Material Thickness x 25 = Tons required per hole

For example, when you punch a .500” diameter hole in .250” mild steel, the tonnage required per hole is 9.82. (3.1416 x .500 x .250 x 25 = 9.82 tons)

The formula above is for punching mild steel. When punching stainless steel, a multiplier factor of 1.4 is required. For example, 9.82 tons x 1.4 = 13.75 tons per hole.

The orientation of the shape is the position of the shape in relation to the front of the punching unit.

For example, when ordering an obround punch, select whether Point X is at the front of the unit or the side of the unit, as shown below:

Point X at front of unit

Point X at side of unit

The guide has two slots at 0 and 90 degrees. The pin in the punch fits into one of these slots to orient the shape. Regardless of how you order the orientation of the shape (Point X at front of unit or Point X at side of unit), you can utilize either position.

Quali-Tool manufactures C-frame style press tooling. Unittool is a trademark of Unittool Punch and Die Company, Inc. Quali-Tool, Inc. does not own this trademark.