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need drilling advice
- Thread starter Will5567
- Start date
- Replies 11
- Views 2,617
Finegrain
Diamond
- Joined
- Sep 6, 2007
- Location
- Seattle, Washington
Well, cobalt HSS is going to be low 60's RC so no wonder they aren't working 
.
You need carbide.
Regards.
Mike
.You need carbide.
Regards.
Mike
G
Guest
Guest
Need a lot more info. Diameter, depth, lathe or mill? Number of parts? I would just check out Guhring's website.
stephen thomas
Diamond
- Joined
- Jun 3, 2001
If this is just a "hole" with no close tolerances, the cheapest method is to use a carbide tipped masonary drill. Reshape the tip on a diamond wheel to neutral rake. (They come strongly negative) It does not take much. Run it fairly fast, but becareful not to run it so hot the braze melts and the tip comes off in the hole. 
smt
smt
DMF_TomB
Diamond
- Joined
- Dec 13, 2008
- Location
- Rochester, NY, USA
.
depends on size and depth of hole. sometimes carbide end mill down .002 up .001 repeat til depth , blow out dust chips often, if you try for too much usually just break end mill. down .002 up .001, repeat as needed. drilled out many a broke tap that way. greatest danger at hole end when broke tap is free often tap piece jams in against hole side and end mill breaking it
RC Mech
Stainless
- Joined
- Jul 21, 2014
- Location
- Ontario, Canada
Seriously, a solid carbide drill. You haven't been given any guidance re revs because you haven't mentioned a diameter.
That's like trying to cut glass with a piece of styrofoam.
redlee
Titanium
- Joined
- Apr 2, 2009
- Location
- Beaver County Alb. Canada
Im sure I saw that on youtube!
Atomkinder
Titanium
- Joined
- May 8, 2012
- Location
- Mid-Iowa, USA
I second the YG Dream Drill for awesome results.
I've never tried the cheapo option(s) for creating holes in hardened steel.
I've never tried the cheapo option(s) for creating holes in hardened steel.
Mike C.
Diamond
- Joined
- Nov 25, 2004
- Location
- Birmingham, AL
You may actually get through it with the cobalt if you run REAL slow (like 25-30ft/min), use some cutting oil and dub the lips (gently touch the cutting edge of the drill to the grinder with the drill body perpendicular to give a neutral rake angle to the cut, like for cutting brass). I have drilled out roll pins this way, but you'll probably go through several sharpenings. The cut is going to be just sort of a scrape instead of a curly chip. When it stops cutting (which may be 15 seconds), resharpen the drill and go at it again. This would be OK for a couple of holes. As mentioned above, go with carbide if you have more than a couple to do.
cmccull166
Hot Rolled
- Joined
- Mar 29, 2013
- Location
- NW Pa
'm trying to drill through 4150CA Steel thats hardened to 62C. I've killed 2 Cobalt bits in about 5 min to make basically no progress. any suggestion on the best type of bit to use to get through this stuff?
Thanks,
Will[/QUOTE]
google die drills they are economical and designed for hardened materials.
and keep air blowing towards the point to cool and clear the chips.
You can also use a spend carbide end mill
Thanks,
Will[/QUOTE]
google die drills they are economical and designed for hardened materials.
and keep air blowing towards the point to cool and clear the chips.
You can also use a spend carbide end mill
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