Drill bit sharpener?

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hockeyoligist2

Senior Member
Do any of you resharpen your drill bits? I have to drill stainless quite often and if I'm not real careful I tend to dull them. I would like something small and fairly cheap so I can keep it on my truck. I have looked at a few different ones at HD and Lowes. I bought one from Northern Tools about 6 years ago and it didn't do too well. Any recommendations?
 

nakulak

Senior Member
I have a fancy schmancy drill bit sharpener, but I never use it. I use a grinder, and then when they are done they go in a bucket (mostly to never be seen again.
 

realolman

Senior Member
If you're gonna drill stainless, you gotta turn it slow and take a big bite.

We had a drill doctor at work a little while ago. Although I didn't personally try it, it didn't last too long, and got sent back. They said it was no good.

Small ones you might as well pitch, but from about 5/16 - 3/8 and up you can sharpen them on a grinder with pretty good results. Keep the water handy.

I've had good luck sharpening ship augers and wood speed bits with a file.
 

hockeyoligist2

Senior Member
realolman said:
If you're gonna drill stainless, you gotta turn it slow and take a big bite.

We had a drill doctor at work a little while ago. Although I didn't personally try it, it didn't last too long, and got sent back. They said it was no good.

Small ones you might as well pitch, but from about 5/16 - 3/8 and up you can sharpen them on a grinder with pretty good results. Keep the water handy.

I've had good luck sharpening ship augers and wood speed bits with a file.

I am good at sharpening a bit on a grinder, I used to be a tool and die man, when I was young. I wouldn't want to haul a grinder around on a work truck (heavy, grinding wheel easily damaged). I resharpen them when I'm at the shop but sometimes out in the field I need to sharpen a bit instead of driving 20 miles or having extras on my truck. I do keep extra 1/4 inch bits for my hole saws but the boss won't let me buy extras in other sizes.
 

bkludecke

Senior Member
Location
Big Bear Lake, CA
Occupation
Retired Electrical Contractor
I treat most drill bits as disposable items and keep plenty of extras handy. Now and then I can get them buy the ton in yard sales but I usually just order them abunch at a time when I'm running low.
 

electricalperson

Senior Member
Location
massachusetts
your boss should provide you with drill bits. i usually use a file to sharpen my auger bits and i normally just throw the twist drill bits away when they get dull and replace them with something new. i buy the cheap black ones from sears usually.
 

ultramegabob

Senior Member
Location
Indiana
small drill bits I just throw away and buy new ones, I sharpen my nail eaters with a 1" upright belt sander, my unitbit is about trashed so I experimented with it a few days agoe by sharpening it with a file, and I got a few more holes out of it, but it needs replaced.
 

tkb

Senior Member
Location
MA
I sharpen my auger bits with a file and twist bits with a drill doctor. It works pretty good. You have to set the bit in the holder just right so it will sharpen correctly.

I learned from a tool and die tool maker how to sharpen twist bits by hand on a bench grinder.
He also hated it if he saw me drill out a hole on the machine he was building then wobble the drill to make the hole bigger.
 

wawireguy

Senior Member
Drill sharpening.. Waste of time unless it's a auger bit. Then a file will do. I'd just buy better bits and learn to not burn them up.
 

e57

Senior Member
hockeyoligist2 said:
~I have to drill stainless quite often and if I'm not real careful I tend to dull them.
Me too.... Cobalt bits, and lots of oil on super slow. Also I have found that stainless is one of them metals that will 'self-temper'. i.e. it will get harder as it heats and often harden as it cools slightly before the chip even gets off the drill - and the harder it gets the hotter the bit gets and looses temper hardening - vicious cycle.

So lots of flowing cutting oil - if you see smoke or the oil is thinning - you're too fast or pressure too hard and not enough oil. You may need to cut - wait - cut - wait..... I have also taken to chilling the work and bit prior with a blast of dust-off in a up-turned can - then oil - cut - wait....
 

Brady Electric

Senior Member
Location
Asheville, N. C.
Drill bit sharpener

Drill bit sharpener

I used to sharpen my bits but I found that once they get dull sharpening doesn't help for very long
I buy nail biting bits now and they last about one for every new house
Bits should be called nail finders
Somehow nails find new bits very easy
For small bits and masonry bit I do use the Drill Doctor which I have good luck with
Semper Fi Buddy
 

hockeyoligist2

Senior Member
wawireguy said:
Drill sharpening.. Waste of time unless it's a auger bit. Then a file will do. I'd just buy better bits and learn to not burn them up.

I said I dull them, not burn them up. They are very expensive, high quality Starrett drill bits. Letter, number, and fractional.
 

jdsmith

Senior Member
Location
Ohio
I don't see why you'd want to sharpen bits in the field. I have a drill doctor 750 that I use for 1/4" - 1/2" bits. Anything over 3/8" or 1/2" is faster on a proper grinder once you learn the technique. I bought some of the toolroom type twist drill drawers that I have in the shop with at least 6 drills of any size that I use very often. The drills from the cabinet are used in the shop or can replace a dull drill in an index that is taken to the jobsite. Dull bits go in a plastic cup off to the side and when the cup is full I get out the Drill Doctor or bench grinder and sharpen them all and put them back into the cabinet.

The drills you buy are important too. Most drills that supply houses or hardware stores carry are carbon steel of at least HSS that aren't hardened properly. Order HSS, bright finish drills from McMaster-Carr, MSC or another tooling supplier. These will be better quality than most locally available drills and aren't all that expensive. Don't buy and Titanium Nitride or fancy colored coatings - those aren't necessary unless you're running the drill for long periods in a machine tool. I like split point 135 degree drills because they require less force when drilling by hand. The split point will break off and create a large dull spot where it was before the rest of the edge gets too dull. When this happens swap it out for another drill and it won't take too long to sharpen. If the tip of the drill is purple, brown, or straw colored it has been overheated and will take a long time to sharpen back into hard material - you have to remove at least 1/8" of length where the metal has been softened. Look at a speed and feed chart for the material you are drilling and diameter of drill to avoid overheating drills in the future. If you're dealing with employees, supply 600 RPM Hole Shooters to minimize the drill bit speed.
 
I know it's a bit different, but we send our CNC bits to a machine shop to resharpen them. They can cut the tip right, and follow the cut all the way up, if they're good.

It's easier and cheaper than buying new bits all the time. At least CNC bits.:grin: :roll:

Most of the people I've talked to about the Drill Doctor weren't impressed by them. They say you only get a cut or two before they go dull again.
 
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