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Knockout Punch Sharpening

16K views 8 replies 8 participants last post by  llseamless 
#1 ·
I've got a vintage Greenlee punch and the instructions talk about sharpening it by holding it to the side of an abrasive cut-off wheel. Anyone ever tried it?
 
#4 ·
I've sharpened my KO punches and dies many times.

The smaller sizes are harder to do, and don't come out as good.

The punch part is the most difficult, I use a 1" belt sander, and an 80 grit belt. Sand the face of the punch, as best as possible. Don't sand the edge at all, it'll make it smaller, and it won't shear the metal being cut.

The die part is really easy, just hit the face of it until the inner rim feels sharp.

They cut quite a bit easier when I'm done, especially the larger sizes.

Rob
 
#9 ·
I've sharpened my KO punches and dies many times. The smaller sizes are harder to do, and don't come out as good. The punch part is the most difficult, I use a 1" belt sander, and an 80 grit belt. Sand the face of the punch, as best as possible. Don't sand the edge at all, it'll make it smaller, and it won't shear the metal being cut. The die part is really easy, just hit the face of it until the inner rim feels sharp. They cut quite a bit easier when I'm done, especially the larger sizes. Rob
Thank you I use a screw on. 3 1/2” hole punch and a 2 3/4” hole punch for my gutters. It’s the same thing but my guage is a little less. My knock out was made by a fabrication company over 16 years ago. I’m going to try this sharpening method. I’m just going to go slow as it’s just one side of the punch part. I’m not going to touch the outside and just let it slide up from the cup! Thanks guys!
 
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