Results 1 to 23 of 23

Thread: Sharpening drill bits

  1. #1
    Join Date
    Mar 2009
    Location
    Texas
    Posts
    5,611

    Default Sharpening drill bits

    Nothing special. Just a pile of old small (up to 1/2) bits.

    Does anyone freehand sharpen? Or is a little cheap bench grinder jig worth having for $20?

    I've got various stones, a bench grinder, and a bench-mount belt sander

    I'm not interested in a larger investment. And my drilling needs are modest.

    Thanks

    Screenshot_20200921-082350.jpg

  2. #2
    Join Date
    Apr 2005
    Location
    Hills of Vermont, USA
    Posts
    36,416

    Default Re: Sharpening drill bits

    I picked up a DrillDoctor at a yard sale for $5. Works pretty well.

    Similar to this: https://www.northerntool.com/shop/to...8aAmYsEALw_wcB
    "If it ain't broke, you're not trying." - Red Green

  3. #3
    Join Date
    Jan 2003
    Location
    New Zealand's Far North
    Posts
    9,729

    Default Re: Sharpening drill bits

    I freehand sharpen down to about 3/16" using my 6" bench grinder. I was taught by an old school British ship's engineer who gave me a 1/2" bit to practice on until I started to get a feel for it. There are plenty of instructional videos on YouTube these days. Lots of practice is what gets a good result.
    I would rather have doubt than be certain and wrong.
    Richard Feynman.

  4. #4
    Join Date
    Feb 2005
    Location
    Abbotsford, B.C.
    Posts
    5,367

    Default Re: Sharpening drill bits

    Eclipse, (British) and Drill Doctor work well.
    Harry Bryan did a peice in WB a few years back.
    basil

  5. #5
    Join Date
    Mar 2006
    Location
    West Sacramento, CA
    Posts
    7,473

    Default Re: Sharpening drill bits

    Some time back I read a description online by an old guy who described how to use the pads of your index finger and thumb on one hand, as a guide. You briefly pinch the shank of the bit hard enough to leave an impression and then rotate the bit in that depression with your other hand, as you hold, first one flute bevel, and then the other, to the stone at the right angle. Touch, twist, done, one side after the other. And the technique uses a built-in temperature sensor so you won't burn the edges of the bit.
    Speak softly and carry a mouthful of marbles.

  6. #6
    Join Date
    Sep 2015
    Location
    Viroqua, Wisconsin
    Posts
    169

    Default Re: Sharpening drill bits

    Anyone have a preference for Cobalt over black oxide over TiN-coated?

    I gave up on TiN a long time back, find Cobalt seem to stay sharp longest but tough to sharpen unless on a diamond wheel.

  7. #7
    Join Date
    Apr 2000
    Location
    Southampton Ont. Canada
    Posts
    6,832

    Default Re: Sharpening drill bits

    I learned it in school.
    Long twin curlies in mild steel or you didn't pass
    Just when you thought you had it,the instructor would wreck it and make you do it again.
    R
    Sleep with one eye open.

  8. #8
    Join Date
    Feb 2015
    Location
    Anacortes, WA
    Posts
    40

    Default Re: Sharpening drill bits

    I learned to sharpen twist drills many years ago in a Vo-Tech School machining night course. The teacher taught it free hand on an electric grinder and he was quite good at it. I didn’t pursue the machinist trade but I have been sharpening drill bits these many years for woodworking purposes, doing it free hand on a hand cranked grinder, cranking the grinder with my right hand and holding the drill bit against the grinding wheel with my left. In my experience, the quality of sharpening job matters much more when you are drilling steel than when you are drilling wood. I have found that a fairly half-assed sharpening job will generally work just fine drilling wood and I stopped worrying about doing a perfect job of it decades ago. I don’t doubt that there are those who hold a different point of view.

  9. #9
    Join Date
    Sep 2003
    Location
    Somewhere in South Central PA
    Posts
    3,566

    Default Re: Sharpening drill bits

    Quote Originally Posted by bluedog225 View Post
    I have one of these that is several decades old and in the original box. It came in a lot of tools I bought at an auction. It works well.

  10. #10
    Join Date
    Jan 2011
    Location
    Norwalk CT
    Posts
    1,571

    Default Re: Sharpening drill bits

    Quote Originally Posted by Ron Williamson View Post
    I learned it in school.
    Long twin curlies in mild steel or you didn't pass
    Just when you thought you had it,the instructor would wreck it and make you do it again.
    R
    Like learning to file a handsaw in apprenticeship training...the instructor would saw a piece of 2X4, say "Good job" and then run the saw over a brick. "Do it again".....

  11. #11
    Join Date
    Jan 2007
    Location
    Brewer, Maine
    Posts
    92

    Default Re: Sharpening drill bits

    And I thought meanness was restricted to my medical school professors...

  12. #12
    Join Date
    Oct 2017
    Location
    Virginia Beach, Va
    Posts
    12

    Default Re: Sharpening drill bits

    Free hand.
    If you can sand curves in wood, you can sharpen a drill bit. The only critical part is the leading edge needs to be higher than the flank. Seems obvious but this is where rookies crap it up! Introduce the drill to the wheel from the flank and work back to the edge without ever going past 90*. Use the corners of the wheel to reduce your point (this is a little trickier). Also, follow the angle formed by the current edge. The other big mistake is to put a larger angle by over working.

  13. #13
    Join Date
    Jun 2003
    Location
    Central Coast, Ca
    Posts
    29,184

    Default Re: Sharpening drill bits

    Sharpening large twist drills can get tricky by hand, like over 3/4"
    And sharpening small twist drill bits can can tricky by hand, like under an 1/8"

    edit to add:
    fwiw when sharpening by hand I always start at the cutting edge and work back into the clearance angle.
    This cuts off the burr.
    I often use a 4 facet grind to separate the cutting edge from the clearance angle, and I often "dub" the rake angle (or twist) to keep it from grabbing in soft material like lead, copper and brass.
    A drill sharpening gauge for a couple of bucks is a must have if you are going to much of this.

    Last edited by Canoeyawl; 09-27-2020 at 09:08 PM.

  14. #14
    Join Date
    Mar 2017
    Location
    Loon Lake, Washington
    Posts
    150

    Default Re: Sharpening drill bits

    I do 'em freehand. The old feller what taught me said "Just grind off whatever don't look right"

    I used to do down to about 1/8th! Not anymore!
    Keep the bit wet!

    I ground this big 'ol bit much flatter for boring out a muzzle loader barrel. Get the right grind, and it goes likedy-split.


    SAM_6560.jpg

  15. #15
    Join Date
    Sep 2020
    Location
    MKE WI
    Posts
    10

    Default Re: Sharpening drill bits

    If I’m in a hurry and not super worried about a clean hole, I freehand them. Otherwise, I really like my Drill Doctor. Takes a little practice but is well worth it. I tend to let dull bits pile up and do them in a batch.

  16. #16
    Join Date
    Nov 2004
    Location
    Port Townsend WA
    Posts
    14,462

    Default Re: Sharpening drill bits

    I agree about the Drill Doctor DosRenshos. I had a batch of about three hundred old drills I picked up a a garage sale for twenty five bucks. I invested in a Drill Doctor and spent about five days bringing them back to life one winter when the shop stove kept the coffee pot warm. That thing sharpened every one to a T ! I can heartily endorse the Drill Doctor for being hassle free and efficient as well! I don't think I will ever need to buy a new drill again unless I need an odd size!
    Jay

  17. #17
    Join Date
    Jun 2010
    Location
    PNW, an island west of Seattle
    Posts
    2,550

    Default Re: Sharpening drill bits

    Will a Drill Doctor tool sharpen a split point bit?

    Jeff

  18. #18
    Join Date
    Sep 2020
    Location
    MKE WI
    Posts
    10

    Default Re: Sharpening drill bits

    Yes, it does do split point. Very well I might add.


    edit: the design has changed apparently (mine is called the “classic”) but they still do split point

  19. #19
    Join Date
    Nov 2004
    Location
    Port Townsend WA
    Posts
    14,462

    Default Re: Sharpening drill bits

    I second that observation and doff my cap to the "Drill Doctor"! It is one of the best tools I have ever had in my shop!
    Saves a ton of hassle in buying new drills or hand holding a dull one against a wheel.
    Jay

  20. #20
    Join Date
    Jan 2011
    Location
    Norwalk CT
    Posts
    1,571

    Default Re: Sharpening drill bits

    I always thought Drill Dr. was a gimmick. Saw it on TV one night around 2am and dismissed it.

    Might have to get me one...theres coffee cans full of old dinged up bits in the boneyard under the bench

  21. #21
    Join Date
    Nov 2004
    Location
    Port Townsend WA
    Posts
    14,462

    Default Re: Sharpening drill bits

    Try it, you'll like it!
    Bird

  22. #22
    Join Date
    Apr 2015
    Location
    St. Helens, Oregon
    Posts
    2,458

    Default Re: Sharpening drill bits

    Looks like they have three levels. Any recommendations on which to get for a hobbiest?

  23. #23
    Join Date
    Sep 2020
    Location
    MKE WI
    Posts
    10

    Default Re: Sharpening drill bits

    Ehhhhh, hard to say without laying my hands on the new ones but just looking at the specs I’d go with the 500X.

    The new design looks nicer to use than my classic.

    A full Benjamin might seem like a lot for a bit sharpener but I’d buy it again in a heartbeat.



    AND: thanks to google I found out they have left hand chucks too!

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •