Pre-Pierce

Whilst piercing refers to cutting or slitting metal, there are several different types of specific piercing operations, some of which can be carried out before roll forming, and some after. Lancing, perforating, notching, and trimming form some of the most common piercing operations. 

Lancing - lancing refers to shearing the metal without separating it from the workpiece and bending it to reshape it; lancing can be performed by a press with punch and die.

Perforating - perforating metal means to create multiple closely-spaced, small holes within a workpiece; this can likewise be carried out by a punch and die.

Notching - notching refers to removing material from the edge of the workpiece; this can be done in conjunction with bending the material so as to form a shape (similar to lancing, however notching utilises a complete cut). 

Trimming - trimming is a finishing operation, meaning it occurs after forming, since it shears excess material from a stamped part to complete the end product shape.

There are many reasons why you would choose to pierce before forming the metal during the manufacturing process, these include:

• Pre-piercing can be carried out in one linear, continuous operation, saving both time and money
• Removes the need for secondary piercing operations
• High consistency and repeatability across products, since it can be performed in a continuous line 
• Allows for holes or slots that cannot be created on the formed shape, such as hollow profiles 
• It is easier to punch holes in a flat shape; less skill is required and there is a lower risk of damaging the finished product