I've done this before and found it incredibly difficult.

Do I need a special drill? I will need one longer than normal to get at the fastener.

The hole will need to be 5mm or so.

 

tunsten carbide drill bit and some rocol rtd cutting compound if doing lots of them , and not to fast either

 

I would use a center punch on a hard surface underneath then use a small carbide or titanium coated bit.Make sure the bit has something to bite into and make sure the bits are sharp!You want to go very slow and if it gets hot use a bit of 3 in one oil to help cool it.Use a quite a bit of down ward pressure.

Chip

 

Slow, keep it cutting, if it starts to "rub" then it will blunt the drill. Plenty of coolant.

 

you can have it on fast if using a battery drill, but just press and release, press release, press release trigger. stops it getting as hot and melting the tip, maybe go through with a smaller drill 1st and use cutting fluid or some oil... or spit if u dont have any !

 

Cheers lads, will look at a decent drill bit, the only ones I can find so far are just HSS.........http://www.screwfix.com/prods/31100/...2mm-Pack-of-10

 

5mm....normal drill bit, slow speed, watch for the ****** as it breaks through, and the most important thing is plenty of lubrication as this will keep the bit cool which will stop it burning out.

If it glows red you have gone to fast lol.

 

Had to drill 15? 6 mm holes in some 3mm plates (316) , started with punch then 3mm 'titanium' bit and then 6mm same , took bit time - worked ok

No lube either

 

use dewallt bits, expensive, but havent found anything that comes close yet.

http://www.screwfix.com/prods/59901/...-HSS-Drill-Bit

 

You can buy bits that are specially ground for stainless, they have different angles ground to the point. They drill ss like it was mild steel, and if you use them on mild steel.....hang onto your drill. I have some in the car, will see if I can see any details tomorrow if you need them.

 

Cheers mj, that would be useful. Do they do long ones, circa 100mm?

 

You are building a nuke by enriching you own plutonium aren't you?!?

 

Aye, right

Drilling out a fastener that doesn't want to come using the proper removal tool, so as to screw in an "easy-out".

 

I would look at cobalt drill bits, they're designed for stainless, engineers at work use them all the time as nearly all the gear there is stainless for health reasons.

http://cgi.ebay.co.uk/DEWALT-DT5940-...item3a61b5f36c

Cobalt drill bits offer the best heat resistance and rigid thick web design for drilling in extremely hard and abrasive materials such as treated stainless steel (precipitation-hardened), cast iron and titanium

 

Alcazar,

Drill bits are 'dormer Hss a108'

 

This seems a good price..

http://www.screwfix.com/search.do;js...hbutton=submit

 

They need to be over 110mm long.

I've found some on Screwfix, £8+ a set of ten, plus a local guy sells them singly at £2.50 each, 135mm long. Might buy a set, they are Dormer branded, and will be useful anyway.

My Easy-Out is crap though, the threads at the end of the one I need are chewed up to hell.

Must be a crap cheap set............thought they were hardened