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Greg, I have a set of step drills and they are the cats pajamas for drilling
mild steel sheet. I love them so much I don't dare try using them on stainless and dulling them.
Willie
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Hi,
This is a good job for a punch and die. But for a one-off job like this, I would just use a regular drill bit. And just sharpen as needed. You may need to hit the backside burrs with a grinder to remove, but for this application, pretty is secondary.
dalee
dalee, proud to be a member of MetalworkingFun since Aug 2012.
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316 is pretty hard on drills. You will end up sharpening whatever you use quite a bit on 150-180 holes. Cobalt will help. If you're freehanding, carbide drills will break too easily. BUT, I have successfully taken a carbide tipped masonry drill and sharpened it for metal use and had good success. You just have to keep them cool enough not to melt out the braze. Low speed, high feed.
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Willie,
Drilling stainless sheet is a pain regardless of what you use. If the holes aren't too far from the edge of the sheet, it might be worth your time to make a punch. Either use an off the shelf punch and die, or make them yourself out of O1, then all you need is a couple of pieces of bar stock spaced apart to hold them and some means of retracting the punch.
Tom
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Thin stainless is a propper pain to drill
Once the drill gets blunt and heats the plate it goes very hard
I would try making a punch and die as Tom sugested
John
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(11-04-2012, 01:06 PM)Tony Wells Wrote: BUT, I have successfully taken a carbide tipped masonry drill and sharpened it for metal use and had good success.
I really don't relish the thought of drilling 180 holes in the sheets to begin with, let alone having to make a punch and die set and do it all over again. Not for this project anyway.... I'm just too lazy.
I wouldn't mind sacrificing a masonry drill though to do it in one step though.
How do you go about grinding one for metal use Tony?
I think I have some cobalt drill point end mills somewhere, but would hate to destroy one of those in the process.
Willie