I”m trying to drill 9/64ths holes on what appears to be stainless steel. Actually a hand-saw blade.
What’s the best drill bit to buy? I purchased a “fancy”bit at Lowes (either titanium or unobtainium – sumpthing fancy anyway) but by the time I get a hole, I’ve got a burned bit.
Replies
Cobalt bit, cutting fluid, slow speed, and STEADY FIRM PRESSURE.
Nazadr is exactly correct, But I would add that you also use a center punch, to give the bit a starting point. Bits love to wander and skitter when starting into stainless.
Work Safe, Count to 10 when your done for the day !!
Bruce S.
This may sound a bit out of the ordinary but SS steel tends to work harden if punched with a normal center punch grind your punch into a triangular shape that will shear the metal rather than compress it a normal HSS drill bit at the right speed and some lube should work fine.
Regards from Melbourne Aus.
You can make it fool proof but not idiot proof
Handsaw blades are typically spring steel in the high 40s to low 50s Rockwell scale. The cobalt and titanium bits will work. You may get 1-2 holes done before sharpening the bit if it is at the upper end of hardness. More if it is at the softer end.
You can use a smaller bit as a starter hole which will help prolong the larger bit's life. Some fluid and it'll get done.
Take care, Mike
Definitely not stainless steel. There is a technique we called spot annealing where you take a piece of flat end steel rod and chuck it in a drill press and spin it on a spot until ot turns blue. Basically you are taking the the temper out of that spot and it will drill easily with regular a hss drill bit . There are some good metal forums out there that deal better with these type of questions. Just pop your question on google.
Edited 11/8/2006 7:43 am ET by RickL
Edited 11/8/2006 9:44 am ET by RickL
Carbide bits work well without the extra step of annealing, too. I hesitated to recommend them as they can be brittle in the smaller sizes and they cost a bit more. MSC, McMaster carry them. I depend on them to drill saw blades everyday.
I can usually get ten or more blades drilled between sharpening, which amounts to about 30 holes.
If one has a solid carbide router bit of the proper diameter, it too can be sharpened for use as a drill bit. They work great as well.
As for spot annealing, you can use a HSS drill bit inverted, no oil as a lube for obvious reasons. Allow to cool naturally else if forced it will merely reharden.
Take care, Mike
I know...I have a metalsmith, machinist background as well as furniture making.
I probably should have chosen to point my message to 'All' but it was your post which prompted my response. I wasn't trying "teach" you something.
Take care, Mike
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