Sharpening Drill Bits

[peteretep 6,521]

Whats the best way to sharpen drill bits? I am constantly smashing my drill bits into stuff thats too hard and making general trouble for myself. I was shown how to sharpen a drill bit a long time ago but I have forgotten exactly how, and I recall its easy to fuck it up. There are heaps of all kinds of weird machines on trademe/google including hand powered and electric. But whats your best method or tool??

[nzed 1,669]

Go buy yourself a drill doctor 750x.  

You can still get yourself into a lil bit of trouble with it but on a while relatively easy to use and last well ...  

Better off to just teach yourself or get someone to show ya the basics.

I'm oldschool. I still use a bench grinder and an angle gauge but that's because I'm drilling s/s alot and need tolerance.

It is easy once you understand the reasons for the angles...   but like anything depends how fussy u want to be..  

Better to buy a decent set of drills and just actually learn how to use them semi properly... 

 

[Mark_Fleming 273]

Drill Doctor is the answer......mine is parked beside the drill press and gets constant use, 30 seconds to sharpen and away you go.....buy a used one off ebay, ship it in through youshop then buy a 110v converter off trademe......

[tortron 55,500]

I use bench grinder and some lines I scratched into the guard for angles

[JoKer 18,067]

all of the above, self taught also & I make mine into 'wood' or dowel drill for obvious reasons, with a tip & outer cutting lip (might resemble a Spot weld drill) vs the common "V" where you need the cutting edge taller & sloped back

[kicker 18,256]

I need something like this, I had to drill 4 holes in some steel that had concrete immediately behind it, fucked a few bits getting it done.

[Mark_Fleming 273]

also, do a google on using a masonry bit to drill hardened steel.....yes, it works.....

[peteretep 6,521]

What would the difference be between a drill doctor and one of the NZ voltage machines not branded as drill doctor? Drill doctor is just the OG one so its best and everyone else is a copy?

[nzed 1,669]

Unsure. But I can say we have two of the drill doctors here and I know they have survived a punishing. One has also seen a fair bit of carbide as well.......... 

What sort of price difference are we talking?

 

[Get it done 1,299]

Cobalt is the go ! Good drill selection and speed should limit sharpening .

A home made scratch guage and a bench grinder is all that is needed, be carefully to select the correct stone grit , a fine one for small bits and a coarser for larger bits .

A cup of water can help with heating of drill edge , make sure bit doesn't blue or it won't hold a edge .

 

[ajg193 8,214]

I sharpened a drill bit with a flap disk on an angle grinder once. Took 4 attempts before it was close enough to actually drill a hole. Would not recommend.

[Muncie 9,124]

I learned from 2 proper oldschool engineers. The first was my boss the second a guy he contracted who i learned all the good tricks from. 

A bench grinder with a fine stone is a must i use the side of the stone, eyeball the bit parallel with the stone using a scooping motion commit flip it over usually 2 dabs its bang on. You'll get to know when the helix of the drill is resting on your finger right and time it takes to put an edge back on.

Ideally you want to put fuck all heat into it bit of water handy helps. Once a drill bit is thrashed and turned blue drilling holes it wont hold an edge long.

[yetchh 5,971]

39 minutes ago, ajg193 said:

I sharpened a drill bit with a flap disk on an angle grinder once. Took 4 attempts before it was close enough to actually drill a hole. Would not recommend.

 

I've done it with a flap disc and thought it did a good job, also done on a 1mm cutting blade, masonry disc, diamond disc etc.. only in a pinch tho, I'd otherwise use the bench grinder..

[ajg193 8,214]

What size drill bit? This was a 5mm with an intended angle of 135 deg. I can imagine something bigger being a bit easier

[Seedy Al 18,026]

Isn't the key 59 degrees? 

So if you weld two two nuts together that is usually close enough to make it work for a while. 

I don't even use a gauge although I should.  However pretty much every drill I go to use at work is super fucked unless I have already sharpened it and stashed it away lol.

Lube is great by the way while drilling. .....

 

 

Smerk.

[73crownwagon 4,074]

^ as what he said! I do the same with the two nuts tacked up. I do need magnifine glass to do smaller then 3mm tho. Just need fine stone on grinding wheel. 

[ajg193 8,214]

8 hours ago, Seedy Al said:

Isn't the key 59 degrees? 

So if you weld two two nuts together that is usually close enough to make it work for a while. 

I don't even use a gauge although I should.  However pretty much every drill I go to use at work is super fucked unless I have already sharpened it and stashed it away lol.

Lube is great by the way while drilling. .....

 

 

Smerk.

Yeah usually 118 deg, but this bosch drill specified 135 for some reason. They cut insanely well when sharp.

 

The worst thing for drill bits seems to be hand held drills.

[datlow 19,490]

9 hours ago, Seedy Al said:

Isn't the key 59 degrees? 

 

yeah but its measured the other way around?!

[ajg193 8,214]

44 minutes ago, datlow said:

yeah but its measured the other way around?!

If you recall highschool geometry, you will know that it doesn't matter which way you measure the angle:

"vertically opposite angles are equal"

 

Unless of course you were just referring to how you measure the total angle, if so then carry on

 

[datlow 19,490]

Yeah yeah nah wotz geometry 

from vertical so half the angle of the fan dangle