I need to drill a 3mm (or 1/8) hole in 58-62 Rockwell steel. Can't 
anneal it.

Will carbide do? Do I need to use diamond?

If so, sources for a suitable drill? The hole must be pretty accurate, 
maybe even reamed.

Ideas? It's only one or at most two holes, so buying EDM or similar 
machinery, much as I'd like to, isn't practical.

Thanks,

-- Peter Fairbrother

> I need to drill a 3mm (or 1/8) hole in 58-62 Rockwell steel. Can't 
> anneal it.
> 
> Will carbide do? Do I need to use diamond?
> 
> If so, sources for a suitable drill? The hole must be pretty accurate, 
> maybe even reamed.
> 
> Ideas? It's only one or at most two holes, so buying EDM or similar 
> machinery, much as I'd like to, isn't practical.

Hi Peter,

Is this still about your liquid fueled rocket motor ?  How's progress been 
recently ? I'd be interested to hear an update and I'm sure lots of other people 
here woulf be too.

Cheers,

-- 
Boo

On 15 Jul, 20:41, Peter Fairbrother  wrote:
> I need to drill a 3mm (or 1/8) hole in 58-62 Rockwell steel. Can't
> anneal it.
>

If you can get hold of some Diagrit Hardcut drills they'll make short
work of it - they are designed for drilliing out HSS taps, etc. using
normal workshop equipment.

I've not seen any advertised for years but I'm sure one of the tool
manufacturers must do something similar.............

On 15 Jul, 21:27, Boo 
wrote:
> > I need to drill a 3mm (or 1/8) hole in 58-62 Rockwell steel. Can't
> > anneal it.
>
> > Will carbide do? Do I need to use diamond?
>
> > If so, sources for a suitable drill? The hole must be pretty accurate,
> > maybe even reamed.
>
> > Ideas? It's only one or at most two holes, so buying EDM or similar
> > machinery, much as I'd like to, isn't practical.
>
> Hi Peter,
>
> Is this still about your liquid fueled rocket motor ?  How's progress been
> recently ? I'd be interested to hear an update and I'm sure lots of other people
> here woulf be too.
>
> Cheers,
>
> --
> Boo

"Peter Fairbrother"  wrote in message 
news:487cfd58$0$2529$da0feed9@news.zen.co.uk...
>I need to drill a 3mm (or 1/8) hole in 58-62 Rockwell steel. Can't anneal 
>it.
>
> Will carbide do? Do I need to use diamond?
>
> If so, sources for a suitable drill? The hole must be pretty accurate, 
> maybe even reamed.
>
> Ideas? It's only one or at most two holes, so buying EDM or similar 
> machinery, much as I'd like to, isn't practical.
>
> Thanks,

I have used carbide drills in fairly hard (blued high carbon) steel but I 
don't know how it compares on the Rockwell scale. Eternal Tools are good for 
both carbide and diamond drills.

If you haven't used carbide drills before I suggest you buy two or three of 
them. They are extremely brittle and will shatter at the slightest hint of 
mis-alignment, wobble, or side load, and yet they need to be pushed into the 
work firmly to cut well.

Cliff Coggin.

On Tue, 15 Jul 2008 20:41:23 +0100, Peter Fairbrother
 wrote:

>I need to drill a 3mm (or 1/8) hole in 58-62 Rockwell steel. Can't 
>anneal it.
>
>Will carbide do? Do I need to use diamond?
>
>If so, sources for a suitable drill? The hole must be pretty accurate, 
>maybe even reamed.
>
>Ideas? It's only one or at most two holes, so buying EDM or similar 
>machinery, much as I'd like to, isn't practical.
>
>Thanks,
>
>-- Peter Fairbrother
Greetings Peter,
Carbide will indeed work. The drill should have straight flutes and a
split point. Use lots of high steady pressure. The chips will exit red
hot and almost molten. A rigid setup is a must. If the hole is a
through hole then you will need to back up the part with steel that's
as hard as the part. Softer steel risks breaking the drill.
Cheers,
Eric

I've used the "drill anything" bits with success. They look like
masonary bits. The technique is to use lots of speed and lots of
pressure. The friction heats the metal which goes soft and the drill
then cuts it. I've seen files and hacksaw blades drilled like this.
Mind the swarf though, it can be white hot.

John

On 15 Jul, 20:41, Peter Fairbrother  wrote:
> I need to drill a 3mm (or 1/8) hole in 58-62 Rockwell steel. Can't
> anneal it.
>
> Will carbide do? Do I need to use diamond?
>
> If so, sources for a suitable drill? The hole must be pretty accurate,
> maybe even reamed.
>
> Ideas? It's only one or at most two holes, so buying EDM or similar
> machinery, much as I'd like to, isn't practical.
>
> Thanks,
>
> -- Peter Fairbrother

you could try a stellite drill, such as http://www.cromwell.co.uk/DEL0265050A
not cheap at list price, but they are usually discountable, and other
sizes available.

Dave

On 17 Jul, 22:14, dave sanderson 
wrote:
> On 15 Jul, 20:41, Peter Fairbrother  wrote:
>
> > I need to drill a 3mm (or 1/8) hole in 58-62 Rockwell steel. Can't
> > anneal it.
>
> > Will carbide do? Do I need to use diamond?
>
> > If so, sources for a suitable drill? The hole must be pretty accurate,
> > maybe even reamed.
>
> > Ideas? It's only one or at most two holes, so buying EDM or similar
> > machinery, much as I'd like to, isn't practical.
>
> > Thanks,
>
> > -- Peter Fairbrother
>
> you could try a stellite drill, such ashttp://www.cromwell.co.uk/DEL0265050A
> not cheap at list price, but they are usually discountable, and other
> sizes available.
>
> Dave

oops, just notice they are out of stock. must be available elsewhere,
or
direct from delloro
Dave

" you could try a stellite drill, such ashttp://www.cromwell.co.uk/DEL0265050A
 not cheap at list price, but they are usually discountable, and other
 sizes available.

 Dave "

I have some 4mm carbide tig electrodes - they grind much like
stellite, would a 'drill' fashioned from that do?