swipe stamping?

[Med-Pac]

Hi,

We've been contacted by a potential customer that needs in excess of 500,000 parts per year. The pcs. will be roughly 4" x 6" x .375. He has suggested swipe stamping, I'm not sure what that is.

My main concern with this possible project is the tolerance he wants to maintain. +/- .002. To get tolerances that tight on a punching fixture, wouldn't you run a greater risk of problems?

Mike

[apache405]

what material does this part need to be made of and how complex is it?

[PhoenixMetal]

If the parts involve a bend, your customer may have mean to use the word "wipe" and not "swipe." Wiping would refer to a method of bending in which the flange to be bent gets "wiped" up (or down) by the die. This bending operation could be done in a progressive die that punches the flat blank, and does the bends all in one die with no human intervention. This is in contrast to a more labor intensive bending method in which the bends would be done in a press brake.

Regarding the tolerances, if this is a stamped part, there's no reason why you should have significant variation in the size of the blank, so if the part is simple enough, you should be able to handle it. If the part has bends in it however, it could be difficult to maintain perfectly consistent angles, as variations in material thickness and imperfect press ram repeatability can affect bend angles.

Either way, just keep a tight watch on the parts coming out, and if you have any variation, stop the process, figure out the source of the variation, find a way to correct it, and keep going again. There will be a bit of a learning curve, but soon enough you'll develop a stable process that puts out quality parts without headaches.

[juergenwt]

Hard to say without seeing a print, but I believe they are talking about so called " over the edge " forming. Tol. of .002 is very tight. 3/8 thick - air cylinder on the bottom. We would sometimes just change material spec.s slightly to get the desired results.

[Med-Pac]

Thanks for the info guys,

We decided to let this one go. After talking with the customer about our concerns, we discovered that they were not willing to deviate from their current design. That made our decision rather easy.

Mike