drilling silver

[elizabeth towler]

I'm trying to drill a hole through a 4mm thick piece of silver and I have broken about 7 drill bits so far! Can anyone enlighten me as to the proper way of doing this without breaking bits? I have tried small bits to start and moving up and Ive tried wax as a lubricant? The process is getting very frustrating so please help someone?

[CJ57]

Hi Elizabeth
Are you using a pendant drill and what size drill is it?

[pearlescence]

If you are using very small drill bits you will be bending them without realising it most probably. Get the bit into the chuck as much as possible to reduce stress on it and bending possibility then concentrate on keeping that bit perfectly straight...the tiniest bend in a 1mm drill bit and it will snap like a twig. Plus make sure your bits are sharp. Very small bits go blunt very quickly. I reckon five pearls to one 0.7mm bit max.

When I drill pearls or silver I don't use a lubricant but it makes sense to remove the bit, clear out the scurf and allow the piece to cool if it has got hot.
Mind you, 4mm isn't very thick so you should not have big problems

[josef1]

Try using a ball ended burr dont run it to fast if you overheat it the end could fall off in the piece

[mizgeorge]

Try using a ball ended burr dont run it to fast if you overheat it the end could fall off in the piece

That's exactly what I was about to suggest. I tend to do just this - the burrs wear out a little bit faster than they would otherwise, but it's a fair bit quicker and the results are more predictable.

[CJ57]

All of the above! A fine drill through 4mm with a pendant is bound to have movement even with a steady hand. A bench drill would give you more control and I would agree that it may also be heating around the drill

[Dennis]

Hi Elizabeth,
You haven't actually told us what equipment you are using, but a hole in 4.0mm of silver is quite a tall order and requires:
A steady hand,
A sharp twist drill, starting at perhaps1.0mm in diameter,
Lots of lubricant in the form of oil,
Medium speed and repeated partial withdrawal of the drill to avoid continuous stress.

If you don't have a pillar drill, or a pillar drill accessory kit, I would hold your hand-piece horizontally in a vice and push the silver onto the drill. This reverse method will allow you to drill into the silver more steadily.

If you are only using a drill with a bow and string, you should use an arrow shaped drill meant for this, as a twist drill will quickly blunt and overheat. Dennis.

[Dennis]

I was still thinking about this in the night, because some drills in the smaller sizes are just too fragile to use. For instance the HSS mounted drills, smaller than about 0.9mm break as soon as you look at them.

Also, I have been working on very thick silver just now, so I accepted your thickness of 4mm. If instead you meant 0.4mm thickness, then of course the idea of using small round burrs, as suggested above, will do the trick for you. Once you have made the hole it will be easy to enlarge with a twist drill or reamed out with a broach used by hand.

Forums need feed back, so please do let us know how you get on. Dennis.

[medusa]

I regularly drill 2mm holes through 2mm silver and my M.O. Is:
1, Punch with a centre punch or nail
2, Drill pilot with HsS bit (in pendant) which has plenty of oil dripping down it. Go slowly, don't press too hard. Make sure the swarf (?) Is cleared out of the way.
3, Move up to a larger drill and procede as above.

I regularly change the drill bits. I buy them from a cheapo online drill shop £1.50 for ten. They last and work as well as cookies ones at 10 x the price.

[caroleallen]

Where do you get your drill bits from Liz?