Broken drill bits

[Wallace]

Yes, as will most oils. Ensure the piece is thoroughly cleaned afterwards.

[pearlescence]

Hi. I use 0.7mm and 1mm bits all the time. Your bits are probably breaking because you are using a dremel and bending them. Try using a big household drill, a normal drill for putting up shelves. You will find it much easier to hold it straight because any movement is much easier to perceive. You probably don't think you are but even a tiny i degree bend is enough to break such thin bits
Keep the drill bit very short in the chuck too - leaving it long also allows it to distort.
Also change bits regularly. a blunt bit is more likely to break. And those bits go blunt in a strong wind, never mind actually going through something.

[Dennis]

May I just add that it is not necessary to discard blunt drill bits. All you need is a medium or fine diamond disk mounted on a mandrel to sharpen them.

You need to find a way to rest your handpiece in a horizontal position, so that you can lightly touch the bits against the disk in two places as indicated by the previous facets. The angle is not very critical, but the drill is sharp if you feel it bite your skin when turned by hand.

As a result all my drill bits vary in length, but last for years. Dennis.

[ps_bond]

The blue diamond impregnated rubber wheels that are now available in the UK are very good for sharpening drill bits too. Magnification helps to see the angles (and no, I don't just mean a scope!).

If you really want to get silly, you can grind a used carbide burr to make your own short twist drills using a diamond disc to set up the angles & carve the flutes, then sharpen it. Still not entirely convinced it's a good use of time, but it does work well.

[Patstone]

Now you are getting really silly. Good idea sharpening drill bits though, I will have a go at that. Peter I know you like different tools but have you had any dealings with the ring stretchers that you hammer the top of, it looks like a mandrel with steps on, because I was thinking of getting one, cant afford the £150 jobbies, couldnt justify having one of them really.

[ps_bond]

Now you are getting really silly.

I'll have to post a picture of one

Good idea sharpening drill bits though, I will have a go at that. Peter I know you like different tools but have you had any dealings with the ring stretchers that you hammer the top of, it looks like a mandrel with steps on, because I was thinking of getting one, cant afford the £150 jobbies, couldnt justify having one of them really.

Honestly? Never used one, the verdict from people I know who have is that they're pretty uncontrollable. I use a ring mandrel and a mallet or planishing hammer.

[caroleallen]

Waste of money Pat. If you get a proper one, it'll revolutionise your work. Christmas is coming!

[pearlescence]

One Tahitian top quality pearl £50. one 0.7mm drill bit 30p

[ps_bond]

1 carbide short drill bit around £7...

[Dennis]

One Tahitian top quality pearl £50. one 0.7mm drill bit 30p

It seems to make sense put like that Wendy, but I use mounted drills for my handpiece and they cost £2.28 inc. VAT. I am just too mean to fund my suppliers sending their daughters to finishing school in Switzerland, so I sharpen them. Regards, Dennis.