Struggling to drill through stainless steel bolt

[fishkeeper84]

Hi,

I recently bought a old Mini MPi, it's the first car I've ever had and I bought it to learn some basic mechanical skills, along with the fact they're just frigging cool! Anyhoo it's revealing issues around every corner, which is what I need I suppose, the latest is a seized bolt on the ball joint end of the tie bar, I've tried all I can with the access I have (very little) so my last option is to drill it out. I've never drilled into stainless steel before, I quickly found out my HSS bits weren't going to cut it so I bought some cobalt bits and some cutting fluid, I was suprised it barely made a scratch but figured the issue must be my drill, it's a cheapy, a 12V cordless Black n Decker costing £40 about 3 years ago, I tried various speeds, taking my time, I used a centre punch also.

Is it my crappy drill? If so can someone advise me on a adequate replacement please, I'm a total newb and the options are baffling me, I don't have a lot to spend as I've got new tools coming out my rear, the mrs will kill me soon. I was looking at these two:

http://www.screwfix.com/p/bosch-gsb-18-2-li-plus-1...
http://www.screwfix.com/p/makita-dhp453rfw-18v-3-0...

Thanks for any help.
Keep on fishin'

[fishkeeper84]

So it's not my drill?

I was drilling with a 2mm bit, it's a M8 bolt, I figured that was a ok pilot size?

Hmmm, they look very similar to my cobalt bits although I'm not sure if mine have a tungsten and molybdenum base, these are mine: http://www.toolstation.com/shop/p68884

[fishkeeper84]

QUOTE Decent HSS will tackle stainless. You do need a drill with some poke, cordless is seldom up to the task unless it's expensive. If it gets hot then mixing up an emulsion of water and oil (any oil) with Fairy is a good lubricant and coolant. Either squirt it from a squeezy bottle or tosh it on with an old brush now and again. An assistant is useful.

I got some cooling fluid cheers, so in the 2 drills I linked 2 probably won't do it either?




QUOTE Can you get a grinder in there to cut the head off it?

Yup I already did that, also a lot of blunt force, infact both ends now have a slightly flattened end, it's proper buggered.

[fishkeeper84]

QUOTE I'd go for a 3mm bit, you can't put a lot of feed onto a 2mm bit. Drill it in stages so you don't overheat the tip.
Cheers

QUOTE Never had a bolt yet that hasn't succumbed to Mr Angry Grinder and one of these:
http://www.screwfix.com/p/erbauer-cutting-discs-11...
I have these discs but I don't want to cut the mounting as it's a £150 replacement, can you explain a little more.


QUOTE Not a good idea to bolt suspension together with stainless bolts they can snap too easily. Use the correct fixings. Plus it should not be ceased if it is stainless,that is the point of stainless bolts.

It's what was in there so I'm only presuming that it's stainless steel. I've been practicing on a new stainless steel M8 bolt in a vice, not the seized bolt in the tie bar.