Reduce Sheet Marking
It is possible to eliminate or reduce sheet marking. Many overlooked opportunities involve keeping the punch press and tooling clean and in good working order. Let’s look at some press-related and tooling-related suggestions.
The overarching opportunity is really to practice good housekeeping. You need to keep the work surface of the press clear of punching debris like slugs and metal dust, which can cause scratching and sheet marking. Use adjustable height work tables to keep the sheet metal at press height when moving material on and off the press. Program a sheet move to pull the sheet out of the press before changing the tooling. Avoid punching near workholders and in stations adjacent to any forming tools. When possible, keep any taller forming tools away from one another and on a separate side of the turret from piercing tools. Move the material slowly over taller forming dies, and remove the forming dies from the turret when not in use. Finally, use a light spray of lubricant on the top and bottom of the sheet to reduce sheet marking.
Use Mate Slug Free™ dies to avoid or eliminate slug pulling. Nibbling is not only an inefficient process, but it causes punching debris in the turret bores, which is directly related to sheet marking. Demagnetize the punches and dies, and remove any sharp edges around the die that were created by sharpening. Ensure that all of the dies are at the same height by using shims. If you have any open or infrequently used stations, install brush or roller dies into those slots. Replace strippers, especially piercing or lower forming strippers, when they become marked or damaged. Another simple solution to reduce sheet marking is to install soft face adhesive urethane pads on the strippers. Lastly, use light-pressure spring packs when punching soft or delicate materials.
Following these best practices can help you achieve superior piece part quality, which is the goal of any successful punching operation. Download our Solution Bulletin.