Best drillbit for steel
- Thread starter woodlandfarms
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LD1
Epic Contributor
Yep. Pilot hole needs to go all the way through unless you are using a split point bit.
A chisel tip without a pilot hole is not efficient. Cause that 1/4" tip doesnt have any cutting surfaces. You are more-or-less just eroding or chewing away that center portion. Without a BIG drill press where you can apply LOTS of pressure, a chisel tip needs a full pilot.
Even a 3/4" hole in 3/8" plate should take 20 seconds or so. Maybe less. Let me see....
200 rpm, with power feed on a drill press set at a generously slow .005" per revolution.... is 1" per minute.
So yea, shouldnt take but about 20 seconds if you are doing it right. Any longer and you are likely just burning up the bit.
crazyal
Super Member
I wouldn't use a hole saw for that small of a hole either but I have found if you are using large hole saws it works well to drill a 1/4" hole (a couple of drilling 3" or larger holes) just inside of but touching the cut line. It'll allow the oil to carry out the metal cuttings as it drains out of the 1/4" hole. Otherwise you'll need to remove the bit from the hole it's cutting and flush out the cuttings. A second tip for hole saws if not using a drill press is to cut the pilot hole first and then use a smooth 1/4" rod. Doing so will avoid the pilot bit catching on the side of the pilot hole and snapping off.
Like others have said, drill your pilot hole all the way through the material.
Like others have said, drill your pilot hole all the way through the material.
OP
woodlandfarms
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Learning something new all the time....
Sodo
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Yep I like this tip too, thanks!
arrow
Super Member
I wish I had as good as luck with my DD with following the instructions religiously. I swear some of these come out of the factory "spot on" and other one's not so much.. I've never been able to sharpen any bit "as good as new" with my machine.
Sodo
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DrillDoctor to get both sides close then touchup by hand.
OP
woodlandfarms
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So back to my big question, how often do you guys lubricate the drill bit?
downsizingnow48
Elite Member
The dark cutting oil plumbers use for threading steel pipe keeps their threading dies sharp for a long time, and it will keep drill bits sharp for a long time too when used in mild steel. Enco has it in 1 gal and 5 gal containers for much less than the small bottles at the usual retail stores.
I keep the bit flooded with oil using a gravity feed arrangement on the drill press.
I keep the bit flooded with oil using a gravity feed arrangement on the drill press.
LD1
Epic Contributor
Depends on what I use.
Mill has mist lube, it keeps the bit cool.
Lathe has flood cooling.
Drill press or hand drill.....depends. The lube isnt so much to lube the bit. ITs to keep it cool and keep the chips from galling and sticking to the bit.
IF using a drill press, your holes should take ~20 seconds to drill each. One good application at the start of each hole should be sufficient.
If using a hand or mag drill, maybe once every 20-30 seconds. Depending on the type of fluid. There is some that is thin and runs away. Others are thick like honey and stay on the part/bit longer.
