drill bits...

[mechman]

HI waldershelf.
Cant grasp 9yrs years day release on 4 yrs apprenticeship.
Norm

 

[sardine]

I used to do it as an apprentice, all the drills in the factory were used until they were just short Stubbs. But in those days there were no cheap tool brands.

I can't do it nowadays though.

 

[Farside]

I've been keeping my eye in, on and off, over the years. Helped along last weekend by picking up a bench grinder with a very fine wheel on it - that'll do drills nicely.

 

[gordon stephenson]

Quite agree with previous posts, Lots of "tradesmen" don't get a lot if any training on the basic stuff, Grinding drills,filing, chiseling and even how to get a good touch with measuring equipment, But there again some people are just in a job they are not cut out for. no matter how long they get away with it,you wouldn't trust them to do something important,

 

[simplysimon]

I have a bench grinder and if its going to last I don't mind spending the money. But you recommend a decent set of hss and learn how to sharpen them then?

I think it will depend on what you're going to use the drills for and how you use them, if you have a pillar/bench drill, mill or lathe then I would recommend a Dormer A190 No.204 set 1-13mm in 0.5mm increments and you should get them for around £70 if you look around, for bigger than 20mm go for Morse Taper, I personally wouldn't bother with the TiN (titanium coated) bits just not worth the extra cost IMO and it will wear off the moment you use or sharpen them.
but if you just need a hole in a bit of tin or plate and you use a pistol drill then I'd say get some semi cheap Presto International bits they will snap just as well as Dormer but at quarter the price.

cobalt drills are very useful in the right situation and good cobalt drills like Dormer A777 are expensive, not to be use in pistol drills unless you have loads of cash and they will need to be sharpened just like any other dill.

if you are not in a hurry to own a set try your local carboot sale, I've picked up hundreds of £ worth of top make drills for a fraction of the cost and most only needed sharpening, stay away from anything that's burnt on the tip or has big chips out of the side flutes, its also a cheap way of honing your sharpening skills if you'll excuse the pun

other good makes to look out for are Inital, SKF, Capital (CTI), Sandvik, Presto (old Presto Tools), Osborn

 

[Maker]

One of the most effective skills learned was how to create small explosions on a benchtop, using an ashtray and acetylene.

I don't suppose they still teach that?

 

[Bill Edwards]

Buy your nice, shiny set of drill bits.
Then also sharpen every bit you currently own. Use them where possible and keep your best bits for when you need them - i.e for a particular size.
Less important if you use a pillar drill, but this way you have less risk of snapping your good bits. It really is a shame when you snap a bit and no longer have a complete set.

Be careful when sharpening bits, you must not get them too hot. Have some water to hand to dip them into. If you get them too hot you'll end up binning them, so avoid it!
It isn't normally necessary for the usual touch up, however when sharpening a bit that has been broken or that is very, very blunt as some of yours may it can be very helpful.

 

[Maker]

As for sharpening drill bits, what do you think of the sharpeners you can buy, both the jigs that hold the bit to a bench grinder and the electric ones where you just drop the bit in a hole and it does it all for you? I'm guessing they're no match for doing it by hand?

 

[Bill Edwards]

Not used them myself but I have seen someone use the type that holds the bit to the bench grinder.
I have a nice book 'tool and cutter sharpening' which takes a very dim view of sharpening bits by hand.

However, I've always done them by hand and I'm quite happy with the results. The biggest thing to worry about is that you keep both sides even (so the point is in the middle), otherwise it won't work right and you get a hole that is oversize. Arguably, there is no point in having a set of drills in 0.1mm increments then making a mess of sharpening them so they're all out and don't leave holes that are the right size. Handy trick when you need a hole bigger than the bit you have though!

The thing is, eyesight (even with crap eyes) is quite good at seeing when things are off. It's easy to give both sides of a bit the same treatment when grinding, and you can see if you've got it right by eye well enough for any work you will normally encounter.

My suggestion would be to just learn to do it without spending money. Partly because there will probably come a time when you need to sharpen a bit and aren't at your place, or where you have nothing but a sander, angle grinder etc to hand and will then appreciate it when you're able to improvise!
If you aren't happy that you're good enough then look at spending the money if others say they're OK, but you'll probably be quite happy without.

 

[waldershelf]

HI waldershelf.
Cant grasp 9yrs years day release on 4 yrs apprenticeship.
Norm

I carried on doing more qualifications after I finished my apprentiship. The company always supported anyone who want to study, sadly not something that happens today I suspect.

 

[balmerchris]

How to file and how to sharpen drills were the first things I was taught in the British Steel foundation course, that every school leaver who started in BS had to go on in the day. It just seemed such a natural thing to do at the time, that I didn't realise how privileged we were to have it.
One of the most effective skills learned was how to create small explosions on a benchtop, using an ashtray and acetylene.

How do you do that then? Sounds like fun!

 

[Farside]

I don't suppose they still teach that?

Pah, the non-smokers of today don't know what fun they're missing.

How do you do that then? Sounds like fun!

The old pub-sized ashtrays were alloy castings or stampings. Turn one upside down, fill it with a mix of oxy/acet, then waft a lit torch past it.
Done right, there was a satisfying bang and the ashtray would leap about four feet in the air. The course instructor let it go on for a bit, but did point out that sooner or later somebody would lose a digit or an eye, kind of thing. It stopped then.

 

[Maker]

Well, I hate smoking with a passion but I'm sure I can burn something to get some ash, who doesn't like fire.

How do I do it then?

 

[Rocketman]

You guys should have a go on a radial drill with 800mm+ dia 10mm drill for water ways in a tool, the boss is not very happy when they snap.

 

[tflnemesis]

Cobalt bits are very good and do hold their edge longer than standard HSS bits but they are quite brittle and won't stand up to any kind of flexing along their length.
Very easy to snap 5mm and smaller bits in a pistol drill, even in a pillar drill if work is not clamped properly.
Being able to touch up a blunt bit is a very useful, I have even used a disc/belt sander to do it when on a job and the only long bit we have wouldn't drill through balsa wood because my mate doesn't know how to drill a hole without buggering up bits.