Looking for a micro drill set

[Simpo Two]

I need to drill some accurate holes in the 0.4 - 0.6mm range.

I've tried these ones and find they're dreadful - even with the utmost care they just snap after a few holes, sometimes on the first hole: https://www.amazon.co.uk/sourcing-map-0-1mm-1mm-Tu...

These ones proved much better but don't stay sharp very long and I'm not sure the sizes are accurate: https://www.amazon.co.uk/Amtech-F0930-0-3-Micro-Dr...

Does anyone make higher quality micro drills? I found Dormer but the price is stupendous! https://www.arceurotrade.co.uk/Catalogue/Cutting-T...

[dudleybloke]

https://www.mscdirect.co.uk/holemaking/hss/jobber-...

[Simpo Two]

dudleybloke said:

https://www.mscdirect.co.uk/holemaking/hss/jobber-...

Blimey. lots of stuff there! Thanks; will have to spend some time on that tomorrow.

[Zad]

Search Ebay etc for PCB drills (similar to yours). The ones to look for are re-sharpened industrial drills that have fail the minimum-length test in their CNC and been refurbed for sale. They are usually pretty decent for home use. They go down to 0.1mm diameter or so - I can imagine how long they don't last in a Dremel...

I guess industrial ones may be harder and more brittle though?

ETA: Look for the shorter drills, they should be less prone to breakage.

[Simpo Two]

Zad said:

Search Ebay etc for PCB drills (similar to yours). The ones to look for are re-sharpened industrial drills that have fail the minimum-length test in their CNC and been refurbed for sale. They are usually pretty decent for home use. They go down to 0.1mm diameter or so - I can imagine how long they don't last in a Dremel...

I guess industrial ones may be harder and more brittle though?

ETA: Look for the shorter drills, they should be less prone to breakage.

Thanks. In this case I'm using a Proxxon mill drill for precision and being super careful and slow - but the ones with the coloured bands still go ping after 0-5 uses. I think the metal is too cut away, ie the spirals are too deep.

[tr7v8]

I use this one for R/c modelling. Mostly wood.
https://www.amazon.co.uk/Precision-Delicate-Electr...

[tr7v8]

Simpo Two said:

Zad said:

Search Ebay etc for PCB drills (similar to yours). The ones to look for are re-sharpened industrial drills that have fail the minimum-length test in their CNC and been refurbed for sale. They are usually pretty decent for home use. They go down to 0.1mm diameter or so - I can imagine how long they don't last in a Dremel...

I guess industrial ones may be harder and more brittle though?

ETA: Look for the shorter drills, they should be less prone to breakage.

Thanks. In this case I'm using a Proxxon mill drill for precision and being super careful and slow - but the ones with the coloured bands still go ping after 0-5 uses. I think the metal is too cut away, ie the spirals are too deep.

That's what you're doing wrong. Small drills need high speed & careful support. e.g. clamped workpiece.

[Simpo Two]

tr7v8 said:

That's what you're doing wrong. Small drills need high speed & careful support. e.g. clamped workpiece.

The workpiece is clamped and the drill is in a stand. It couldn't be more precise or controlled. By 'slow' I meant lowering the drill very slowly towards the work. I used a moderate speed thinking that a high speed would put more stress on the bit.

I'm drilling (trying to drill) through thin brass strip into wood

[dom9]

Good thread!

I have been looking for some micro drill bits in the 2mm range for holes in 316L.

Hoping to push fit a 2mm dowel into a 1.98/99 hole, for a friction fit.

Thinking that should work and 1.95mm (hole) will be too small/hard.

[Whitefly Swatter]

try these guys
https://www.cousinsuk.com/
watchmaking stuff

[Simpo Two]

Whitefly Swatter said:

try these guys
https://www.cousinsuk.com/
watchmaking stuff

That's a great site, many thanks.

I like Dormer drills so went for those first - then remembered that my chuck doesn't grip really tiny drills so I went for these ones instead (and half the price): https://www.cousinsuk.com/product/jewellery-drills


I did order a set of cheap drills from Amazon (the kind in the flat red box) but none of the ones I tried would drill a hole, and some skated. On close examination they were all broken!

[hidetheelephants]

Simpo Two said:

tr7v8 said:

That's what you're doing wrong. Small drills need high speed & careful support. e.g. clamped workpiece.

The workpiece is clamped and the drill is in a stand. It couldn't be more precise or controlled. By 'slow' I meant lowering the drill very slowly towards the work. I used a moderate speed thinking that a high speed would put more stress on the bit.

I'm drilling (trying to drill) through thin brass strip into wood

The right speed is very important in order to reduce the stress on the drill; having the wrong speed increases it. For a 0.5mm drill into brass the 'correct speed' is in the region of 30,000RPM, so unless you have quite specialist equipment you need to have them spinning at whatever your machine's maximum speed is. It's worth experimenting with a lubricant to see if that helps.

dom9 said:

Good thread!

I have been looking for some micro drill bits in the 2mm range for holes in 316L.

Hoping to push fit a 2mm dowel into a 1.98/99 hole, for a friction fit.

Thinking that should work and 1.95mm (hole) will be too small/hard.

You're not likely to get that level of precision from a twist drill, even a reamer will be doing well without some trial and error. What is the dowel doing? Could it be replaced with a spring pin or similar to reduce the need for a precise size/fit?

Edited by hidetheelephants on Sunday 8th December 10:24

[Simpo Two]

hidetheelephants said:

The right speed is very important in order to reduce the stress on the drill; having the wrong speed increases it. For a 0.5mm drill into brass the 'correct speed' is in the region of 30,000RPM, so unless you have quite specialist equipment you need to have them spinning at whatever your machine's maximum speed is. It's worth experimenting with a lubricant to see if that helps.

That makes sense because the diameter of the drill is very small so the speed of the cutting edge is lower for any given rpm.

Mine only goes to 6,000 rpm but the brass is only 0.4mm thick so it hasn't got far to go.

https://www.proxxon.com/en/micromot/20165.php

I have a Minicraft drill that claims 30,000 rpm but I need the accuracy of a stand, and I don't have one for it.

[hidetheelephants]

Your work bench isn't a production environment, so just doing your best with the gear you've got is fine; as you've found drill bits that small are a pain in the bum. Increase the speed to 6k and try adding a bit of lubricant.

[Geoff391]

Another possible supplier , lots of options if you scroll down

https://innocraftsman.com/products/mini-drill-bit-...

[Tim O]

In a previous life when I worked in the precision machining industry my first port of call for any ‘small’ tooling was Drill Services. Huge range of drills, reamers, burrs, etc. etc.

https://www.drill-service.co.uk/products/drills/mi...


PS you want the highest speed you can get and a very, very fine controlled feed, something much more easily achieved on a machine tool. I don’t think the human hand is able to control feed rate of a 0.1mm dia drill without a very high failure rate.

Edited by Tim O on Sunday 8th December 18:16