"Bob H" wrote in message
...
Ian Stirling wrote:
Bob H wrote:

Lawrence Zarb wrote:

Is there any special drill bit or procedure that needs to be followed
when drilling into stainless steel?



You can use a decent quality HSS drill as well.
Start off with a small/pilot hole, then increase size of drill to full
diameter you require.
Oh, yes use plenty of cutting fluid as well. DO NOT use too much pressure
or you will quickly blunt the drills.

As I have only 35 years experience in engineering I don't know what I am
talking about! so you are free to ignore this.


Plus, there is stainless and stainless, it varies from "what are people
going on about" to "I can't believe it's not diamond".
The first can in some cases also convert into the second, if you don't
press hard enough, and the drill gets to rotate without cutting.
Or if the drill is slightly blunt.
IMO, if you've only got a few holes to drill, too much pressure is better
than not enough.

Also, high speed on an electric drill should not be used for any but the
smallest drills.

Yes there is 'stainless' and 'stainless'. There is, if I remember
correctly 18.8.1 and 18.something else.1. I think the 'something else'
might be 13.

The numbers can have a very wide range, as they represent the percentages of
chromium and nickel in the steel. However, the most common are 18/8, a bog
standard stainless steel, and 18/10, used for food, chemical and marine
applications. If you were using 18/13, you were probably doing deep drawing
work. However, all those are only a small selection from the austentic range
of stainless steels. There are martensitic, ferritic and precipitation
hardening (a special type of austenitic) stainless steels as well. The ISO
standard runs to several pages of tables of different specifications.

Colin Bignell