I'm in trouble.

[grandpascot]

I wanted to replace the locating pins on the header rail of my convertible. The old ones were in a bad way very badly rusted and inevitably on one side both screw heads broke. I have spent a couple of hours trying to drill these screws out and nothing. Hardly a dimple . What are these little devils made of. However I have bought new Cobolt drills today and tried with these. No further advancement and yes I have been drilling very slowly and with lubricant. Any ideas would be much appreciated.

[Budgie]

You'll have a devil of a job as they're made of hardened steel !

[grandpascot]

I am going to try bonding with Araldite after all I have nothing to lose.

[grandpascot]

I am going to try bonding with Araldite after all I have nothing to lose.

[RobThomas]

If you have a Mig welder, try welding an old screwdriver head to the screw?

[colin addison]

Not being funny but you might just try a left-handed drill, if you can find one about the right size, and try changing the angle from side to side etc. If the screw can be started then it will wind out.
I had a problem with the locating pin coming out of the flat plate, the MIG sorted that out with a bit of grinding flat after welding.
Colin

[biomed32uk]

If you don't have access to a welder get a piece of metal, similar diameter to the screw red hot and apply it to the end of the broken screw, several times as that will get some heat into it. When it is hot apply some releasing oil, not WD40 so Plus gas or the like. Even better is 50/50 Acetone and ATF but that means buying and waiting probably.

That may help to crack the rust, the left handed drill bit is an excellent idea, it may just grab it then and get it out.

Good luck.

[grandpascot]

Sadly I don't have access to a MIG but I will try your other suggestions and report back. Unfortunately yesterday I tried to cut off my little finger in the hood frame and whilst I was not successful in cutting it off I did do a fair bit of damage so it will be some days before I can return to the problem.
Thanks for your help it's much appreciated.
Mike

[biomed32uk]

Ouch, hope the finger sorts itself out. I remember doing similar with a bandsaw which also hurt.

If you are allowed to its a good time to keep dousing the penetrating oil on, while awaiting for you to attack it again.

[Matt Tomkins]

be careful about introducing too much heat to the header rail, either with a lamp or with a welder. It's heavily lead loaded.

lead loading.jpg (64.29 KiB) Viewed 2359 times

if it was me, i would first try using a slit disc in a grinder to cut a slot for a screwdriver in the top of it. Failing that, very very gently i would straddle the stub with a nut, surround it with sand to keep heat down, then puddle it full of weld as quickly and gently as possible to avoid melting the lead. then wind out with a spanner.