Slug Free® Dies


Mate Slug Free® dies eliminate slug pulling. Slug pulling is a condition where the slug returns to the top of the sheet during the stripping portion of the punching cycle. The slug comes between the punch and the top of the sheet on the next cycle. This causes damage to the piece part and the tooling. Slug Free dies eliminate this problem.

The Slug Free die has been designed with an opening that has a constriction point below the surface so the slug cannot return once it passes through this point. Once the slug is separated from the punch, it is free to fall away from the punching area. Slug pulling is eliminated.

Left to Right: (1) Material held securely by stripper before punch makes contact. (2) Punch penetrates the material; slug fractures away from sheet. (3) Pressure point constricts slug. Punch stroke bottoms out as slug squeezes past pressure point. (4) Punch retracts and slug is free to fall down and away through exit taper of the Slug Free die.

Mate Slug Free Light™ Dies for Thin Materials

Mate Slug Free Light™ thick turret dies are designed to eliminate slug pulling when punching thin sheet metal material, where the recommended die clearance is less than 0.008(0.20).

The Mate Slug Free Light die works by introducing a series of small protrusions around the edge of the slug. Each protrusion is created by a small angled notch cut into the die opening (See arrow in photo below). As the slug passes through the die, the position of the protrusion relative to the notch changes slightly. This change creates slight pressure between the slug and the die land, which traps the slug into the die and eliminates the possibility of the slug being pulled back through the die. By eliminating slug pulling with every punch cycle, the piece part quality is improved and tool life is increased.