Help! - Broken Bolt

[enut]

I was removing the rear spoiler on my Challenger 1800 when one of the bolt heads broke off. I know this has been talked about before but I am having a tough time drilling into it to remove it. I bought a set of reverse drill bits from Harbor Freight but I can not go in very far. What am I doing wrong, it seems like these stainless steel bolts are a pain to drill out.

 

[Dr Honda]

That's hard stainless. You need a cobalt (8%) or carbide drill to get into it. The Lefty bits from HF are regular HSS.

Just a silly question though..... you are running the drill backwards with the lefty bits... Right?

 

[enut]

Yes, I am running the drill backwards. Do you think that the Lefty bits from HF are ruined now? Where do you recommend I get the bits from?
Thanks for the help.

 

[Dr Honda]

It's probably not ruined... but it may be dull.

When I go into stainless... I will drill the bolt first. (with a smaller drill) then, hit it with the lefty bit.

Unfortunately... I buy dills for my shop, from an industrial shop. Good, split point, cobalt drills are hard to find in your local hardware store.

The other nice thing about cobalt is that they are WAY more ridged than HSS. So... they don't try to "Walk" when you drill.


Actually......... now that I think about it.... I think sears has them. They aren't cheap, but you can buy a single drill for $6~$7.

 

[enut]

What do you think of this from Harbor Freight? It is labelled as a split point cobalt drill bit set.


http://www.harborfreight.com/29-piece-135-degree-split-point-cobalt-drill-bit-set-36891.html