micro drill bit set recommendations

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Jacob

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Need a drill bit 0.5mm ish and wondered about buying a little set to cover a micro range. Any recommendations?
Some come with a pin chuck. Is this essential or can they be used in a drill stand?
n.b. it's for drilling holes for fitting spike pins in a banjo fretboard.
 
I do a lot of this making circuit boards so that's probably a mixed blessing here - doing hundreds of holes on a regular basis probably makes my approach a bit spendy for occasional use.

I find the boxed sets like the "microbox" in the first picture uniformly poor these days. Perhaps 20 years ago you could source useless sets for around perhaps £3 or quality for the £10-15 mark. Nowadays it doesn't matter how much you pay, if you spend more you're simply paying a bigger markup for the same rubbish. HSS just doesn't seem suited to small bits. By the sounds of it you're drilling wood so they'll probably work well enough for the immediate job but mild steel or even brass... forget it.

In any case I would say plan for breakages from the the outset, you want several spares of the right size. I'd steer you towards the bits used in electronics instead, tungsten carbide on common 1/8" shanks. The tungsten gives you a good sharp bit that wears well - handy on fibreglass boards which are hostile to cutting tools - but they are quite brittle. Second picture is how they are usually packaged, third is a variety box set from Amazon of the same thing. The likes of Amazon and eBay are fine for sourcing and likely to give best prices. Some of the "new" bits I've had in the past are clearly resharps but haven't caused any issues, after all their former life will have been in automatic machines and probably replaced to a schedule.

As for how to drive the bits, a pin vice is one option. The mini Archimedes drills used in jewellery work very well and are dirt cheap (CPC link) but the chuck won't take those common shank bits. The reverse is likely true for your drill stand - I'm not sure what you mean there but it sounds like a stand for a handheld drill not a drill press... I'm dubious but if it has no discernible runout and rises and falls perfectly vertically then perhaps.

https://cpc.farnell.com/duratool/d02331/mini-archimedes-drill/dp/TL15768?ost=Archimedes+drill

Most drills designed for this will run at a much faster RPM than you are used to - think about how cutting speed at the bit's periphery goes down with diameter at constant RPM. In the past I used a mini 12v "dentists" drill that tops out at 14,500 but nowadays use a mini bench drill that goes to 8,500. That only cost around £50 from Aim Tools a few years back but appreciate that's an outlay for a one off job. You're likely to find a Dremel a bit cumbersome in this kind of application. You don't need those higher speeds for occasional use but will need to progress slowly and carefully.

Final point, whatever you do make sure the workpiece is held down, you can't get away without simply because you are using tiny drills. Finger pressure is fine but you can't afford the work to lift as you withdraw the drill - that's a quick route to broken bits.
 

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Do you have a Dremel or Proxxon tool and if so, do you also have a 3.0 or 3.2mm collet ?
The little solid carbide drills and burrs for PCB work are excellent but you will likely need the above to make use of them.
 
Bought two sets from China thinking they were rubbish ....
still on the first set......I use em to open up brass carburettor jets....
the pin chuck that came with it was worthless so bought a used one from ebay....
may have been Starret....
 
Thanks for all the info!
It's only a one off (or two off) and I'm not sure of the size so will buy a cheapo set. My drill stand will hold 1mm fine so 0.5 should be OK. I get the point about holding the workpiece.
cheers ta
 
If you have a Dremel, I've found the genuine chuck (part number 4486) they make to be superb, very low runout, well designed, and smooth running at the high speeds you need for these drill sizes. There are lots of cheap clones though that are rubbish (at least the ones I bought first were) so watch out. It only grips down to 0.8mm officially, but below that in my view you should be using those drills that have the coloured rings around them, tapering from a larger shank (typically 3.175mm). You can get good, cheap carbide ones from Aliexpress/etc intended for production PCB drilling.
 
Thanks for all the info!
It's only a one off (or two off) and I'm not sure of the size so will buy a cheapo set. My drill stand will hold 1mm fine so 0.5 should be OK. I get the point about holding the workpiece.
cheers ta
Having tried loads i find by far the best are still dormer but v expensive. I find the circuit board ones very brittle. Heller ones are good as well, particularly for use by hand with a pin chuck, they seem more springy than others. I have only rarely broken one, and i frequently use 0.2. Worst thing, to be avoided at all costs is to have one break off in the hole. You can also get end mills in these sizes, but the cutter is typically very short, only 2-3 mm, depends how deep you need the hole to be.
 
Thinking about it in watchmaking i use a tool which consists of a thin steel disc with different sized holes, plain on one side and countersunk on the other. Its indexed so the selected size hole is on the centre line of in this case a lathe. To cut a hole 0.2 for a new pivot in a 0.5 shaft. You butt the end of the shaft up into the countersunk side, which centres it. Then the drill is guided in through the hole, which both supports it and holds it on centre. You could use a similar idea by drilling a guide hole in a thin piece of steel which could then be clamped into position over your fretboard. Depends how many you have to do I suppose, might not be worth the trouble for a handful of holes.
 
Ta for info. Have ordered a cheapo set but will refer back to this very informative thread if necessary!
 
Bought two sets from China thinking they were rubbish ....
still on the first set......I use em to open up brass carburettor jets....
the pin chuck that came with it was worthless so bought a used one from ebay....
may have been Starret....
You were lucky I think. I bought a set like the Axminster mentioned above. Looking at the tips under a microscope they were all over the place. Dormer ones in these sort of sizes are very expensive, £ 3-5 each depending on the size. If you examine them under a scope they are beautifully machined. I have found Heller ones to be a good compromise between quality and price, they are also more springy and dont break easily. The large shank ones sold for circuit boards are good, and the ones I have are very nicely made but I find them very brittle.
 
If you have a Dremel, I've found the genuine chuck (part number 4486) they make to be superb, very low runout, well designed, and smooth running at the high speeds you need for these drill sizes. There are lots of cheap clones though that are rubbish (at least the ones I bought first were) so watch out.
Actually that's another point I'll raise while I'm commenting, although I don't think it's relevant to Jacob. I recommend keeping those small keyless chucks lubed with powdered graphite. Don't need to get fancy, some fine shavings from a pencil lead are fine. Left dry or even oiled they develop a tendency to lock on to the drill and not release when the pressure comes off so you have to manually push the jaws to release.

Although at small sizes I'll also say I find collet chucks much more satisfactory, a hell of a lot more secure. That mini drill press I pictured above actually has a 1/4” keyed Jacobs chuck, but I use that exclusively with shanked bits.
 
I had a set of the 0.6-1.2 mm (dropped around half, never to be seen again) but I only used the biggest. For banjo spikes you'll want something bigger than 1mm I think.

Just ordered these, 0.8-3mm and two of each size Amazon.co.uk

The pin drill is enough for all my luthier needs, no holes deeper than 6mm. If you can wait a few days I'll tell you if they're any good.
 
Thinking about it in watchmaking i use a tool which consists of a thin steel disc with different sized holes, plain on one side and countersunk on the other. Its indexed so the selected size hole is on the centre line of in this case a lathe. To cut a hole 0.2 for a new pivot in a 0.5 shaft. You butt the end of the shaft up into the countersunk side, which centres it. Then the drill is guided in through the hole, which both supports it and holds it on centre. You could use a similar idea by drilling a guide hole in a thin piece of steel which could then be clamped into position over your fretboard. Depends how many you have to do I suppose, might not be worth the trouble for a handful of holes.
Wood is much easier! I just take some spike (nail maybe?) and poke it into the wood at the right spot. This locates the drill bit point nicely.
 
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