Sharpening drill bits

Jewelry Discussion
1

Hi,

I’ve heard that there is a way to sharpen drill bits, is this really
true? I would love to know how to do this instead of throwing out my
dull drill bits.

Thanks in advance!
Laurie
sweettoothdesigns.com

2

You definitely can resharpen drill bits BUT the small drills used in
jewelry work are very difficult to sharpen verses larger drills.
There are drill sharpening units maid just for sharpening bits but
again, the very small drills used in jewelry are difficult. Take a
look on U-TUBE or just do a search for drill sharpening videos. If
you live near Sequim WA, (south of the southern end of Vancouver
Island, Canada). Some metal arts school teachers or metal shop
operators might be willing to help you and show you how. It is
actually pretty easy, you just have to know what to look for and
what angles to watch and keep. Once you “get it” it is easy to
sharpen your bits, I do it all the time for myself and a number
of other folks. If you cannot find videos to help you figure this all
out, contact me and I will see what I can do as far as a few shots
or a short video or 2. It is really great to be able to do this,
makes me feel good every time I do it and then have drills that are
start and easily drill a nice, clean hole.

john dach

3

find a local sharpening service (a hardware store will have
or buy a drill doctor. I have a drill doctor, I bought
the larger one, that is 100 dollars and it works very well.

Chris

4 
I've heard that there is a way to sharpen drill bits, is this
really true? I would love to know how to do this instead of
throwing out my dull drill bits.

Sharpening drill bits are not difficult, but understanding of
geometry which allows bit to cut, is required. Full description of
drill bit geometry is not required here, so to simplify things it is
enough to say that cutting surface is made of two cutting lips.
These lips form point angle, which in common drill bits is 105
degrees. For drilling gold and silver this angle should be closer to
90 degrees. Another angle to worry about is clearance angle, which
is the angle as result of subtraction lip angle from 90 degrees. The
range of values is 5 to 15 degrees with corresponding lip angles of
85 to 75 degrees.

The actual technique is very easy to demonstrate, but almost
impossible to describe. It is one of those things that have to be
seen, rather than read about. I use separating disk for this and for
precision sharpening I use small sharpening stone. The key is to
position drill and stone correctly in order to form required angles.
The actual process of sharpening takes only few seconds.

Leonid Surpin

5

I resharpen drill bits all the time, even the smallest quickly with
just the flexshaft and an emery disc. First look at the angles on
the face of a new drill bit, to see what they look like when brand
new. This look is your goal when resharpening a worn bit.

I turn the emery disc so it faces away from the handpiece, and then
under a loupe I cut the angle of the cutting edge, taking care to
not overheat the metal. Light, and quick is all it takes. Make sure
the angle of this cutting edge is the same on both faces. Next I cut
the relief faces, to leave the cutting edges.

Keep practicing, and comparing the results with a new drill bit, til
you are satisfied with the results. If you have done it well, the
resharpened bit will cut just like new, and I can resharpen even
shattered bits, if I go slowly, and do not try to grind too much at
once. It takes practice to keep from burning the delicate drill bit.
If that happens, the bitis history.

As soon as you start to drill again, you will know if you got the
bit sharp. If not, it only takes a few seconds to recut it. The
entire process takes far less time to do, than to describe here.

6 
I've heard that there is a way to sharpen drill bits, is this
really true? I would love to know how to do this instead of
throwing out my dull drill bits.

Yes, it’s true. There are essentially three ways to do it:

  1. By hand on standard grindstone. It requires a fair amount of
    practise to acquire the skill and is easier with large drills (bigger
    than about 3/8"). Small drills (less than 1/8") are much more
    difficult.

  2. Using a cheap drill sharpening jig; a typical one is shown
    here… http://www.ganoksin.com/gnkurl/ep7zhz

(note: I’m not endorsing this one, it was simply the first one I
found with Google). There are other types and a Google search will
list lots. The results are OK, but again, they are not good for small
drills.

  1. Using a professional machine. These are expensive and probably
    not what you really want.

IHTH
Regards, Gary

7 
find a local sharpening service (a hardware store will have
or buy a drill doctor. I have a drill doctor, I
bought the larger one, that is 100 dollars and it works very well.

I though we are talking about drill bit sharpening as it pertains to
goldsmithing. In goldsmithing, any hole of any size starts with 0.5mm
drill bit. Later on it is enlarged to required diameter. So when we
discussing drilling, it implies working with drill bit size 0.5mm. If
hardware store could do it and goldsmith could not, what does it say
about goldsmith?

There are two ways to handle 0.5mm drill bit, - to learn to do it
manually, or to use specially constructed jig. I believe that jig is
an overkill because in goldsmithing concerns about eccentricity are
not really there. Whether or not cutting lips are of slightly
different length is not really relevant. In watchmaking it will be
absolutely unacceptable, but it is perfectly fine for pilot holes.
Besides such a jig would be quite pricy ( $1000 and up ) and time
consuming to set up. Therefore I recommend to learn how to do it by
hand.

The natural question at this point, - “what about larger drill bits
?” Once pilot hole is there, enlarging it to required diameter is
trivial. I always drill pilot hole first and then follow with 1 mm
drill. Does anybody care to know when was the last time I sharpened
my 1 mm drill bit? I can’t even remember, few years at least.

Leonid Surpin

8

Hi Laurie

To put it simply it is easy to sharpen small drill bits. But there
are factors to be looked for:

1: Often dull drill bits are dull because during the drilling they
have heated up due to lack of lubricant or too much pressure having
been applied.

I use ‘Magic Cut’ an engineering lubricant. 2: There may be a brown
to blue colour on the end of the drill and / or the twist my be
slightly untwisted. In which case forget it as the steel will not
hold an edge unless you cut the end off with an abrasive disk taking
not to heat the drill end.

If the drill bit has broken, usually leaving shattered pieces in the
hole, which can be removed by boiling in a concentrated solution of
‘alum’ available from any chemist. To sharpen small drill bits I use
a medium ‘Easylap’ diamond, sharpening tool. (Excellent for many
processes.) I hold the dril bit in one hand against my bench peg,
under a strong light, and at such an angle that will allow me to lap
off the part of the drill bit at the required angle. I rotate the
drill bit 90d and lap off the the required angle. I like a strong
light so I can see the two facets clearly and match them exactly.

This may require several pactise runs to get the exact facets but it
is well worth the effort.

David Cruickshank (Australia)
jewellerydavidcruickshank.com.au

9

Hello to all members of Orchid…Ganoksin

regarding “SHARPENING DRILL BITS”

You can purchase the “Drill Doctor” model #DD350X, which is
available from Lowes.

Lowes Item #129482 at $49.98 and can sharpen bits from 3/32" - 1/2"
Small investment, but look at how much you can save over time. Also
available from Northern Toll & Equipment Co. at $59.99 with FREE
Shipping.

Trying to grind by hand, unless you are a machinist is not the way
to go. If you don’t get the proper angle on both cutting edges, you
can actually wind up with a larger hole than intented.

I suggest that you should check out the Drill Doctor as mentioned
above, ‘Good Luck’… Sincerely, Richard Lucas…Lucas Dental
Equip. Co.

10

You can sharpen drill bits pretty much the same way you sharpen
gravers. Chuck the bit in a pin vise, use a hard arkansas stone and
check the angles with a 5x loupe. After a while the angles become
part of your muscle memory.

Elliot

1 Like
11

This is a post of mine from 2006:

I was surprised and delighted to find that a little bit of practice
and an over-sized model enabled me to regrind my broken bits to cut
beautifully: I use a fine stone in the flexshaft for the first cut
(the basic point) and then a diamond cutoff wheel for the clearance
angles. It was very difficult to get the angles at first, as I am
doing mailly 0.5mm (~0.019") drill bits. The trick was to use a new,
big fat drill (~1/2") as my model. That made it very easy to 'see’
the proper angles and set them in my head. As soon as I used the big
one as my guide, the little ones started coming out very well. Before
studying the big one, it wasn’t working so well. The new skill saved
me much time and money over the years as well as being very
satisfying!

Janet in Jerusalem

12

The drill doctor is for drills starting with 1.4 mm, that makes it
useless for bench work

Peter
Spain

13

Thanks Janet!! I am using larger drills to attempt to make a short
video to post on this drill sharpening thread. To learn, big is
great!!!

john dach