nick205
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| posted on 8/3/18 at 12:35 PM |
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Who sharpens their drill bits?
Afternoon all,
I've quite a number of drill bits collected over the years. Some individuals and many in sets - probably 40 bits in total.
25 years ago an old chap tried to teach me how to sharpen them on a bench grinder. He seemed to be very adept at it, I was far less so. I've
since worked on the basis that drill bits a pretty cheap and not worth sharpening. Also I don't have a bench grinder.
I've been looking around and seen various drill sharpening machines for £20-30. They seem well reviewed, but what are other people's
thoughts?
Does anyone have or use one?
Do they work well?
Thanks,
Nick
[Edited on 8/3/18 by nick205]
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obfripper
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| posted on 8/3/18 at 12:57 PM |
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I use a bench grinder with coarse and fine wheels, with practice you can sharpen split points down to 3mm and standard tips on any size.
You can also vary the point angle for different materials which is useful for drilling plastic/grp and cut to a spur for thin materials.
I definately didn't learn how to sharpen bits overnight, and a lot of cheap bits don't resharpen any sense, but good drill bits will
resharpen at least halfway down the flute giving a much longer life.
A sharpening tool generally sharpens 59° standard tips for general use, the advantage split point tips have is larger sizes are useable without a
pilot hole.
There's currently one in lidl for 16.99, that looks good enough with a diamond sharpening stone and accessories to sharpen chisels, knives and
scissors.
Its not as versatile as manual sharpening, but can produce repeatable results with less effort.
Dave
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ianhurley20
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| posted on 8/3/18 at 01:50 PM |
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I bought one of those drill sharpening machines a few years ago - must find out where it is and try it out. When I have a drill bit that is blunt I
keep just sharpening it on the small bench grinder - I also have a set of polishing mops so it does brass door furniture, stainless steel brightwork,
drill bits, chisels (metal ones not woodworking) mends broken screwdrivers, grinds things to fit - on balance I would buy an Aldi/Lidl bench grinder
and use YouTube to teach yourself how to get the best out of it.
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Charlie_Zetec
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| posted on 8/3/18 at 02:28 PM |
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I've got a multitude of drill bit sets - I keep my decent Dormer bits to one side and don't let anyone but me use them, so I know
I've always got a pucka set to hand if needs be. For my regular set (generally Bosch bits) I use one very similar to
this to
sharpen as and when necessary, and they survive very well. I've also bought a cheapo Titan (?) box set of 1-10mm bits by the hundred, and these
get lent out/given to people and used & abused for piloting through wood into brick etc. by me then binned when they're blunted or useless.
Artificial intelligence is no match for natural stupidity!
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nick205
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| posted on 8/3/18 at 03:08 PM |
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quote:
Originally posted by Charlie_Zetec
I've got a multitude of drill bit sets - I keep my decent Dormer bits to one side and don't let anyone but me use them, so I know
I've always got a pucka set to hand if needs be. For my regular set (generally Bosch bits) I use one very similar to
this to
sharpen as and when necessary, and they survive very well. I've also bought a cheapo Titan (?) box set of 1-10mm bits by the hundred, and these
get lent out/given to people and used & abused for piloting through wood into brick etc. by me then binned when they're blunted or useless.
Seems a sensible approach!
I'm thinking a bench grinder is probably a better bet, more versatile. I've learnt other things (resetting car service indicators) from
YouTube so drill sharpening seems like a reasonable bet too.
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ian locostzx9rc2
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| posted on 8/3/18 at 06:16 PM |
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Easy enough with a bench grinder with a bit practice you can get good results.
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907
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| posted on 8/3/18 at 08:53 PM |
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I think your doing ok as you are. Using them and then throwing them away. Thats fine.
O, and if you could buy cobalt drills in future. They're much better.
While we're on the subject, got any jiffy bags? Pop them in a jiffy and post 'em to me.
I've always wanted a set of cobalt butterfly drills. Dead handy they'd be.
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trialsman
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| posted on 8/3/18 at 09:07 PM |
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Here in the States there in a bit sharpener called Drill Doctor that I use. My dad could sharpening them by hand and he showed me how to. I also had
to do it by hand in university. But I can't do it any more The Drill Doctor does a wonderful job on the normal HHS bits from 4mm to 13mm.
Anything smaller than that I just get a new bit. Russ
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Simon
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| posted on 8/3/18 at 10:01 PM |
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I use an angle grinder and a drill. The tip is not to let them get too hot and lose tempering.
Put snapped drill bit in drill, put drill on its side on bench and spin it up while holding it still. With grinder, at 30ish degrees and tilted back
slightly put the general shape back into the bit. Stop the drill and grind back the shoulders.
Takes about 10 secs from a snapped to useable drill bit.
Cheers
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bart
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| posted on 8/3/18 at 11:21 PM |
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Using a bench grinder u can also make a drill cut big than size and also smaller.
I could say it's easy but then I was a toolmaker by trade so to me it's as easy peasey leMon squeeze. Sorry to crow .
P's I can give free lessons if close.
BE ALERT > BRITAIN NEEDS LERTS
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bart
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| posted on 8/3/18 at 11:27 PM |
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To really show off.I can do 3,4,5 flute drills and also left hand flute.
BE ALERT > BRITAIN NEEDS LERTS
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907
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| posted on 9/3/18 at 02:34 AM |
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quote:
Originally posted by bart
To really show off.I can do 3,4,5 flute drills and also left hand flute.
Ah! But can you do butterflies? 
It was 1971, and I was 16. Just started my 7 year apprenticeship.
I was given a box of about 200 drills and shown how to sharpen them. By lunch I'd finished so took the box back to my mentor.
In the afternoon I returned to the grinder with the 150 odd that didn't cut.  By 5 o'clock I could sharpen a drill. 
Paul G
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bart
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| posted on 9/3/18 at 06:10 AM |
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Yep pretty much same as. been there got that T shirt. In the days when apprenticeships where proper like !
Any one used a ball bearing to close a h7 reamed hole that was just oversize
When I did the fitting shop I was put with a guy called "puffing billy" old timer who new just about all the tricks. Got one 12"
hack saw blade a week. If you broke it you got a clip round the head. Ahhhh they was the days
BE ALERT > BRITAIN NEEDS LERTS
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907
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| posted on 9/3/18 at 08:24 AM |
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Quote:- " In the days when apprenticeships where proper like ! "
Absolutely. Makes may blood boil when I hear politicians talk of 1 or 2 year apprenticeships.
They don't know what the word means.
And my reward for paying tax since the age of 16? They move the pension dates on. 
Paul G
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bart
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| posted on 9/3/18 at 08:52 AM |
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RANT START - ohhhhh I so agree about 1 and 2 year thing. I did 5 years then a 2 years as a junior engineer .
got to do all the shops
fitting, machine room , electrical , design office , commercial , on site installs ,
got such a good grounding set me up for life.
did my apprenticeship at VS engineering LUTON , used to make complete production lines for all sorts.
whilst I was there did BL Metro , mk3 escort various Vauxhall stuff -and loads more - used to get to work early I so enjoyed it triff times
weird thing is , I have worked all round the country and abroad - always bumping into engineers that did there time there both before and after me
.
these days 6 week NVQ course and they are experts ! expect flack helmet on!
BE ALERT > BRITAIN NEEDS LERTS
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nick205
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| posted on 9/3/18 at 10:10 AM |
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OK so there's those of you that can sharpen drill bits - I'll admit to feeling like I'd better learn.
Regards Cobalt drill bits, mine are the cheaper HSS ones, hence the trow away attitude I suppose.
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bart
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| posted on 9/3/18 at 11:08 AM |
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Fyi
Regarding colbolt drills . I find them to hard and to easy to snap. I find good quality dormer or other top makes of hss much better and hold an edge
just as long.
If you really want good drills go carbide. Cost an arm and a leg though.
BE ALERT > BRITAIN NEEDS LERTS
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nick205
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| posted on 9/3/18 at 11:20 AM |
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quote:
Originally posted by bart
Fyi
Regarding colbolt drills . I find them to hard and to easy to snap. I find good quality dormer or other top makes of hss much better and hold an edge
just as long.
If you really want good drills go carbide. Cost an arm and a leg though.
Noted.
I guess I'm tight, I go source HSS ones from my local Screwfix and Toolstation. They generally work fine (even more so in my low end pillar
drill).
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owelly
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| posted on 10/3/18 at 08:48 AM |
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I have a set of 'blacksmiths' bits that were fairly cheap and have a short flute on them so are harder to snap so these get abused! I also
have a big box of Dormer bits that have been chucked out at work as folks can't sharpen them. I've also gathered a huge pile of randoms
that seem to accumulate from somewhere. They get dragged out, sharpened and used when I can't find the correct size in the 'sharp'
box.
My advice would be to look very carefully at how the cutting edge works on a drill bit. Look at each edge as a single cutting face. Look at how the
centre of the bit will start a hole and cut into it and realise why if this isn't right, you'll never get it to cut without a pilot. Try
to visualise how each cutting edge will 'peel' the material off and how the other cutting edge will follow it. The cutting edges need to
be proud of the trailing edge (rake) and equal to each other. You can alter the rake to suit different materials but for general jobbing, use two hex
nuts pushed together to give you the correct angle. A shallow rake will take a smaller cut so les likely to grab and snap the bit, or chip the cutting
edge.
http://www.ppcmag.co.uk
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nick205
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| posted on 10/3/18 at 03:55 PM |
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Thanks Owelly.
I've been scouting around a few You Tube videos which cover sharpening bits and also how they're designed and formed to work.
There's definitely more to it than most people might be aware of - probably why a number of people struggle to sharpen them!
Busy looking at bench grinders at the minute so will report back further on this once I'm setup and have had a few go's. I have a few
blunt bits to try without losing too much 
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owelly
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| posted on 10/3/18 at 04:27 PM |
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Start off with a large bit to see how it's supposed to work!
http://www.ppcmag.co.uk
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