Drill Sharpening

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emjaiar

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I’m one of those unfortunates who can’t sharpen a HSS drill to save their life. Has anyone any recommendations for a drill sharpening gadget that a. works, and b. is foolproof. I’ve probably bought most of them, but I thought it worth a try to see if somebody has something I haven’t seen.
 
I had an issue sharpening bits, for the most part it was due to not enough
time spent directly behind the cutting edge, even though I was heavily undercutting them.
Two things synergistic for me which made me get there.

Not holding the bit low enough on the bench grinder wheel, my grinder is on a low bench, and stooping lower more awkward.

Having a look at some bits, and copy... duh, you might be thinking?
Note some bits are ground with a smiley face shape to the flank/lands, and not tapering lands.
Getting that shape is more likely that you are removing material from directly behind the edge,
instead of it just appearing so, which large under cut bits disguising material what's left.

Even though this video is of sharpening using a large angle grinder, the movement is largely the same,
I watched as many engineer youtubers sharpen on bench grinders, but this one is one of, if not the best I've seen for some reason.
I guess its just better video angles or something, but it sticks in there better than others.

AvE,(that incognito gold miner, engineer/frankentooler youtuber feller)
 
I can't freehand sharpen a drill bit to save my life, so I use the Drill Doctor 750X. I wanted the 500X, but no one had them in stock at the time. I've been using the 750X for over 15 years with no problems and am still using the same diamond wheel. I don't bother sharpening bits smaller than 5mm, as they are inexpensive to replace.
 
I’ve looked at the drill doctor several times, but always think I could buy a lot of new drills for that sort of money. Mind you my blunt drill box is getting bigger and bigger:)
 
If you place two hex nuts together, the angle formed is the angle you want your drill bits. Also once sharpened don't forget to back off the rear edge slightly.
 
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If you place two hex nuts together, the angle formed is the angle you want your drill bits. Also once sharpened don't forget to back of the rear edge slightly.
That's close for general purpose cutting most Mild steel, but will give you 120° rather than the 118° that standrd 'Jobber' drills are when new.

If you need a drill bit to cut Aluminium, Brass, Delrin, Nylon . . . the list goes on - most efficiently - then you need to take more care. I can't give you chapter & verse since I am an empiricist so re-grind my drills not to a prescribed angle/rake but to suit the specific application that is my current project.
 
That's close for general purpose cutting most Mild steel, but will give you 120°
Thats how my drills are used, the as new un-ground are for metal but once reground then they become general purpose, now I am into wood then no longer need specialised drills for metal. I was spoilt because I used to have them ground in a toolroom and had a set for harder material like stainless and a set for non-ferrous general but in those days none for wood.
 
My Dad used to sharpen drills freehand on a grinder. But then again he was a time served and indentured apprentice (7 years) at Vickers Armstrong on Scotswood Road near Newcastle, so perhaps that skill was not so surprising.

I suspect it is similar to knife skills with a professional chef. A mate was a pro chef, and when he was learning his trade he wasn't allowed to cook anything until he demonstrated sufficient skill in prep with a knife.

But I can't sharpen drills like my Dad to save my life! He's long gone alas, so he can't teach me.
 
i can sharpen by hand but it take s me a while to get the feel back if i havent done it for a time. I also have a drill doctor, i find the drill doctor gives good consistent results but if i have lots to do by hand is quicker. I cant say i regret the drill doctor its reliable. Bigger drill bits are expensive and almost all my drill are dormer etc bought second hand so very rarely sharp.
 
I'm half reasonable at sharpening drills, I look at a new one first, then try to copy the angels whilst fresh in my memory. I generally don't bother doing really small drills. I buy them in bulk.
 
I can't freehand sharpen a drill bit to save my life, so I use the Drill Doctor 750X. I wanted the 500X, but no one had them in stock at the time. I've been using the 750X for over 15 years with no problems and am still using the same diamond wheel. I don't bother sharpening bits smaller than 5mm, as they are inexpensive to replace.
I would add a vote for the drill doctor. It is pricey but it works. I also sharpen very small drills by hand but use a fine diamond lapping disc on a modified bench disc sander. This might help you as it removes a tiny amount at a time and you can see clearly if you are doing it correctly. Helps to hold small drills in a pin vice.
 
I remember this from the toolroom as an apprentice. I was given a 1/2 drill and told to sharpen it, i was at it for around two hours before 'Harry' was satified. He then gave me a 1/16 drill, after about another two hours he laughed and took it awayand said we just throw those away and get a new one. 73 now and can still sharpen a drill.
 
I remember this from the toolroom as an apprentice. I was given a 1/2 drill and told to sharpen it, i was at it for around two hours before 'Harry' was satified. He then gave me a 1/16 drill, after about another two hours he laughed and took it awayand said we just throw those away and get a new one. 73 now and can still sharpen a drill.
,, same for me,, I worked with one of those Harries back in the 60s, at the time thought he was a difficult old b,,,,,,,,, but I"ve turned into one,,
 
save ur money and buy HSS with Cobalt.....really not much more......
once u've mullered them it dont matter....
Must have sharped thousands of drill by hand even the odd milling cutter...only sharpen down to 2mm now....only cos of eye sight.......lol....
It just takes practise and more practise....
when instructing a newbie, I tell em to buy 2 sets of drills from the likes of Lidil.....
keep one set new and sharpen the other....copy the new sets angles etc...
once ground try drilling with em.....u'll soon learn...
 
go to a car boot sale or similar pick up a bunch of knackered drills and keep practising on something it doesn't matter if you make a muck-up of. About 8 to 10mm is a good start size.
 
Amazed so many guys are sharpening drill bits. The only drill bits I have sharpened in the last 10 years are the augers from my brace and bit. And I hardly ever use them. I don’t sharpen drill bits and I don’t clean paint brushes. I justify this to myself by telling myself the replacement cost is built into my pricing and my time is best spent in production and quoting. However, if I’m really honest with myself I may be just inventing a commercial reason in order to avoid jobs I don’t like doing. Not sure.

I probably buy one of these at least once a year.

D422ED5B-8248-4479-AFC4-576D8327C045.png

When I am fitting joinery I’ve made into a masonry background I tend to offer up a timber section to the wall and drill through using a timber bit to mark the wall by drilling 5mm into the plaster/masonry to mark out where I will drill later with an SDS bit. I can sometimes chew through 5 timber bits an installation doing this. Pretty wasteful I suppose. But I used to mark these out by predrilling and then using a sharp spike to mark the wall and occasionally it was hard to find the mark I’d made. Maybe I should be saving all of these blunted bits and donating them to you guys.
 
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I would be ashamed to admit that as my 'practice' :eek:

It is the attitude that pervades the minds of those that have no regard for resourses (scarce or not) simply because 'I can pass the cost on, so it doesn't affect my profit'.

It also contributes to inflation !
 
I justify this to myself by telling myself the replacement cost is built into my pricing and my time is best spent in production and quoting.

When I requested quotes to paint the exterior of my house, one of the vendors provided an incredibly detailed list of the costs. He was at the high end of the "reasonable" zone for the quotes I received. One of the line items in the consumables section of the quote was €350 for Hilti SDS masonry drill bits. When I asked why he wanted to bill me for new SDS drill bits, he told me he had to drill holes in my concrete walls so he could insert anchors to attach the scaffolding and only used new bits for each job.

I told him if I'm paying for the bits, I wanted to see new Hilti bits when the scaffolding arrived and I wanted the bits when they were done with drilling the holes. He refused, so I rejected his offer. Had he not made the new bits a separate item in the quote, I would not have thought about it.
 
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