Sharpening metal drill bits

[formariz 11,849]

This is something that most of us need to do sooner or later. There is no need to buy any special or dedicated equipment for it most being time consuming to set up , expensive and producing less than optimum results. The easiest drill bits to sharpen are the regular metal twist bits and the hardest are wood  Cook Pattern Augers which most people don’t even know what they are.

 For regular drill bits all you need is a regular grinder. As for angles most of us should just duplicate existing angle although I use different angles depending type of metal bit is to be used on. Important things to keep in mind first if all is to go slow and do not burn bit. This is specially true with small bits since it happens fast. Once burned they are done for and will never hold an edge for long. Next is to do both edges evenly and keep center correct. Then make sure that heel of cutting edge is relieved so only cutting edge is offered to metal being drilled. This is done by gently rocking bit on grinder removing more material from heel of cutting edge. When done correctly ground part should be slightly curved and not flat. A flat edge although it will cut will not last long since there is no support behind the edge and bit will shutter as it cuts specially on a large bit. Last but not least use side of wheel not the edge . It’s easy to establish and maintain correct angle on side of stone just by sight. It requires a bit of practice but it’s easy,  I am actually doing it with one hand on the video and holding phone with the other.. On the video below I do it to a bit with badly crumbled edges and then on next video is the testing of it. 

  Edited September 11, 2020 by formariz

[SylvanLakeWH 24,109]

Great video!

 

Appreciate the tutorial!!!

[953 nut 51,624]

6 hours ago, formariz said:

make sure that heel of cutting edge is relieved so only cutting edge is offered to metal being drilled.

        Starting each pass on the heel and working toward the cutting edge is the secret to success.      

[oliver2-44 8,851]

 

@formariz Thank You for sharing all the special tools and experience you use in your craft.  I enjoy learning new techniques to use in the shop. 

At yard saIes' I'm a sucker for antique solid wood basket case furniture to restore.

I'm no way near the craftsman you are, but learn something new with each piece I work on. 

I guess restoring basket case furniture and basket case tractors back to their original  beauty kind of go together.   

[formariz 11,849]

29 minutes ago, oliver2-44 said:

 Thank You for sharing all the special tools and experience you use in your craft.

You are very welcome. Glad to see that it is useful to others. So many people are intimidated or reluctant to try and service tools they use on a frequent basis and wind up discarding them or paying to do it. I have a friend who recently took 10 knives to a hardware store advertising "professional" knife sharpening. Paid $75.00 to have knives come back with uneven edges and burn marks. They just took them to the grinder and butchered them. A total ripoff and ruined knives. Knives , handsaws, chisels , bits, anything for that matter is relatively simple. One just needs to understand how a tool works and what is needed for the metal to cut in that specific tool. Some require a lot more experience such handsaw sharpening ( along with good vision on that one) but it is still simple as long one understands how it cuts.

I'll do a couple more threads on the other types of bits such as Fosteners ,Brad Points, and Augers.

[oliver2-44 8,851]

@formariz  I especially look forward to a thread on sharpening Auger bits.  I have quite a pile of them I've picked up at yard sales over the years.  I've sharpened a few as I've needed them, but they definitely need some work.

[formariz 11,849]

55 minutes ago, oliver2-44 said:

@formariz  I especially look forward to a thread on sharpening Auger bits.  I have quite a pile of them I've picked up at yard sales over the years.  I've sharpened a few as I've needed them, but they definitely need some work.

Sure thing. They are my favorite drill bits for wood by far. Greatest bits and greatest value  since one can pick up hundreds of them real cheap at mot flea markets.

[John2189 405]

I was taught in high school metal shop to never use the side of a grinding wheel.  We’re they wrong?

[lynnmor 6,764]

18 minutes ago, John2189 said:

I was taught in high school metal shop to never use the side of a grinding wheel.  We’re they wrong?

That has been the rule for many years.

 

Besides safety, it is difficult to dress the side of a wheel on a bench grinder.  Having a properly dressed wheel will give a better grind with less chance of burning.  I was taught to grind a drill entirely opposite of what was posted in the video, that is grind on the face of the wheel starting at the cutting edge and then drop opposite end down.  Since I started my tool & die shop 35 years ago, I have used high end drill grinders for drills from .028" to 3/4". larger drills I still do by hand.  Drill Grinders

[formariz 11,849]

57 minutes ago, John2189 said:

I was taught in high school metal shop to never use the side of a grinding wheel.  We’re they wrong?

Yes that is the rule. However we are not talking about serious heavy grinding here. Small drill bits up to 1/2" here generally much smaller once in a while. Anything bigger than that I do it on the honer grinder which runs horizontal and has a rough side. I never had to dress the side of any grinding wheel i used for the last 30 years because of grinding drill bits which is basically all I do using the side.  For me the side of the wheel allows one to actually face the edge of bit and have a clear view of what i am doing . A matter of preference. If uncomfortable with it the wheels edge will work also. Method is the same. How one feeds it to the wheel in my opinion is also a matter of preference. It can be successful either way. Akin to honing a chisel in figure 8 , circular motion, linear motion or side to side. Taking concerns of stone wear aside it all works .Its one's comfortable level to keep chisel at the right angle that will dictate what motion is used.