Sharpening DRILL Bits...?

Post by **blueangelical** » Mon Jul 31, 2006 10:23 am

Hiya., just a quicky.., how do you sharpen drill bits, do you have to use a tool like this..

http://www.screwfix.com/app/sfd/sea/sea ... +sharpener#

Post by **tickman** » Mon Jul 31, 2006 10:52 am

do not need a tool, just a grinding wheel (bench grinder) and you hold the bit to the wheel and twist as you grind!
just practice!
john.

Post by **blueangelical** » Mon Jul 31, 2006 10:58 am

tip facing the wheel, is there a special angle or just follow the lines..

Post by **Alec** » Mon Jul 31, 2006 1:06 pm

Hello B.A,

from memory for general purpose drills it is 58 degrees, and just follow the slight slope which is the clearance angle. Be sure to grind each flute to the same length or it will drill oversize unless you are following a pilot hole.
Certainly, with practise it becomes quite easy and will save a lot of time and\or money.

Alec
P.S., in engineers terms, they are called drills, without the 'bits', I think that is more a carpentry term?

Post by **blueangelical** » Mon Jul 31, 2006 9:00 pm

58 degrees, and just follow the slight slope which is the clearance angle. Be sure to grind each flute to the same length or it will drill oversize unless you are following a pilot hole.

-

, have to get me 'tracter thingy out.,

thanks for the info...

Post by **Kevin** » Tue Aug 01, 2006 2:33 pm

It takes a lot of practice to get it just right and then you have to be used to using a Bench Grider at close quarters as they can be a dangerous piece of kit.
The wheel also needs to be dressed (wait for the remarks) regularly so it will be suitable for sharpening the drills correctly so the attachment is probably a good idea for the novice.
However if you are ok with self sharpening the cheats way to get the angle is to use a Hex nut held flat to the wheel (not switched on) and then scribe a line along the next flat and this will give you a good guide, not quite 58% but 60% will be fine.

Post by **blueangelical** » Tue Aug 01, 2006 8:11 pm

It takes a lot of practice to get it just right and then you have to be used to using a Bench Grider at close quarters as they can be a dangerous piece of kit.
The wheel also needs to be dressed

- have attached wifes panties but they just keep flying off...??

However if you are ok with self sharpening the cheats way to get the angle is to use a Hex nut held flat to the wheel (not switched on) and then scribe a line along the next flat and this will give you a good guide, not quite 58% but 60% will be fine.

-

so the attachment is probably a good idea for the novice.

- think I'll get it.., many thanks for your remarks.......

Post by **andyreeder** » Fri Aug 04, 2006 5:04 pm

TOP TIP
If you put two hex nuts together flat side to flat side the inverted Vee shape ^ of the nuts under the two flat you put together should be the angle the drill should be sharpend to.

Post by **blueangelical** » Fri Aug 04, 2006 8:35 pm

TOP TIP
If you put two hex nuts together flat side to flat side the inverted Vee shape ^ of the nuts under the two flat you put together should be the angle the drill should be sharpend to.

- shouldn't different drill bits be sharpened to different angles though...? eg, for hard materials, metal 88 degrees

Post by **Alec** » Fri Aug 04, 2006 9:46 pm

Hello BA,

yes that's true but for most general use the angles quoted are used.

For a detailed list look at :- www.tapdie.com/html/drills_guide.html

Ther are one or two other tricks such thining the web to make easier driling for larger diameter drills and grinding the face edge to a negative rake angle which suits harder materials and brass or cast iron.

Alec

Post by **RogerRust** » Sat Aug 05, 2006 10:28 am

I was taught to sharpen drills years ago (many years ago) by just touching the fluke of the dril to the wheel and then flicking it off upwards to give it an edge then turn the drill round and do the other fluke. Finally stare at the point of the drill to make sure its even.

With practice this is completed in less than 10 seconds, dont forget you are only putting a sherp edge on the drill not grinding it down so little and often is the solution. The specialist engineers where I worked used to did this exercise every time before starting any precise job.

Part the problem is we leave it 'till to late before sharpening the drill.

Post by **blueangelical** » Sat Aug 05, 2006 2:27 pm

cheers rog, mine are well blunt

"For a detailed list look at :- www.tapdie.com/html/drills_guide.html
" - cheers Alec, all this for a drill bit, cor......

Post by **Kevin** » Sat Aug 05, 2006 9:36 pm

by just touching the fluke of the dril

Flute of the Drill I think you meant Roger.
Plenty of practice is needed but its best if you are shown how, and not everybody masters it easily I have seen some interesting shaped holes caused by those that said they knew how to sharpen a drill, and for those that dont know a badly sharpend drill does not drill a round hole believe it or not.