Cobalt bits.

U

UPSTARTCROWE

Joined
Oct 17, 1999
Messages
122
I spoke knives to my machinist friend again. He said Titanium-nitride coated Cobalt drill bits will cut steel best and last longer. He also showed me how to use 30 weight oil as a coolant when I drill with my 3/8 drill. I have been just drilling and sharpening the bit when it stops cutting.

Which drill bits are best? Has anyone used screw bits (shorter and more rigid).
 
About the only thing that will drill through hardened steel is a carbide drill bit. A coolant is needed for those as well. Most of our drilling needs are when the steel is in an annealed state so rarely are carbide bits necessary, but, when you need them, you need them.
I just buy a bout 4 or 5 each of the sizes I need so I always have them around. I would never use all the bits in a drill index. I don't have any fractional bits at all. Everything I have is either metric or number size.


------------------
C Wilkins
................
I don't care about no fightin' in Bosnia, I don't care about no trade with China! I just want to know when "they" are gonna do something about these God forsaken FIRE ANTS!!!
 
i use polished cobalt bits for drilling, always do your drilling before heat treat. that's when it's the easiest. i also have carbide spade bits(the type of spade for steel)
 
I've been using a combination of Dremel drum sanding and drilling to skeletonize my handles. I was hoping to find an easier/quicker way. My drill bits seem to wear out quickly even though I am working on annealed O-1.
 
I use Rocol RTD cutting fluid and slow drill speeds with HSS drill bits.

When the bits are at the end of their life I take them to the forge, untwist them and hammer them out to make small woodworking tools!
smile.gif


I hate to waste all that M2.

Roger
 
I use a lot of different design drills in my machine shop. Different point angles for different materials. I also have a machien that can sharpen the drills to the geometry that I need for a specific job. ( Not one of those little drill sharpeners, this machine was over $2500.00 and all it does is sharpen drill bits:eek) Anyway, if any member would like to have me sharpen up a drill or two for them, all they have to do is send it to me and I'll do one or two for free. I Do sharpen for lots of other shops so you'll get a professionally sharpened drill that will cut better than the new ones. If you're iterested in sharpening a bunch of drills, let me know as I'm very reasonable and will also give a discount (10%) to any forum member.
 
You must log in or register to reply here.
Back
Top