Prevent Slug Pulling with the Right Die Clearance

Proper die clearance allows for upper and lower fracture lines to connect. The typical stamping industry rule of thumb is to use 10 percent material thickness as clearance between the punch and die button, but this guideline does not take into account variable material types.

5/28/2019

Slug pulling is a perpetual and costly challenge for the stamping industry. Pulled slugs can wreak havoc on stamping operations – damaging parts, causing tool failure, and leading to production losses. Slug pulling results when a scrap of metal (or slug) produced during piercing operations sticks to the punch and comes out of the die button or matrix during the upstroke. Multiple factors may lead to slug pulling, including vacuum pockets caused by trapped air, lubricants that are too thick, punches that are not demagnetized after sharpening, or weak ejector springs.

Read the full article in Fabricating & Metalworking

May 28, 2019