Broken Screw Heads

[1970 Safari]

While having nothing better to do, I decided to check how secure these screws were on the door sill of my 1970 Safari.

Well, I should have stopped after the first one snapped off, but NO!!, I had to continue on to see if it was just a fluke or my bad luck....as you can see it was bad luck...I broke off a second one. Now with only one left I decided to start...I'm NOT stupid!!! smile

Question- any ideas on how to remove the shaft of the screw inside the hole or how to get another screw in there to help hold the jamb. OR should I just leave it alone and hope for the best. The door still functions properly and the shell has not flown off as I travel down the road....YET!!!

Oh Yeah what kind of screws are they, the head is pretty big and I would think they are wood screw threads into the plywood floor??

Thanks, and I will no longer try to tighten things that are not loose!!

[CRH]

I would take a steel punch and give the screw shank a whack or three with a 3 lb hammer and see if it would punch through. If so, replace with a larger diameter screw.

If that failed, I would try to drill out the screw shank and replace with a larger screw.

[AWCHIEF]

You can try a broken screw remover (google it) or drill them out.

[DaveMc]

I'd spray penetrating oil on them for a few days. WD-40 if it's all you have, PB Blaster is about as worthless. A brand called Kroil is head and shoulders above these, but I've only found it online. Anyway, little WD-40 daily for a few days. Day 2 & 3 use a punch/drift and give each broken screw a good rap while you're out there to spray it.

If they are broken off cleanly, this next step is easier. Take a center punch and hammer and put a good divot in the center of the screw shank. This will guide your drill bit.

I'd pick up a set of cheap left-hand drill bits from Harbor Freight, Northern Tool, etc if you don't have any. They help back the rest of the screw out as you drill. Start small and get a little bigger. If you don't get action from the first couple bits (largest of which should be a little more than half the screw diameter), you could tap an EZ-Out into it if the aluminum threshold isn't in the way. If it is, keep going up in size on the left hand bits til it all comes out. The screw will eventually be thin enough to pick out with tweezers,etc.

That may be overkill, you might try WD-40 once and give it a go. Forgot they're only in wood, but likely pretty corroded and all you need to do it break them loose.

Don't feel too bad, I did the same thing on head bolts of an old engine. That was a learning experience for sure.

[CRH]

Kroil does penetrate well. You can't keep it in the can. It bleeds through the crimped seam in the metal can. I have a can leaking on my bench right now.

[joel]

I probably drilled , punched and extracted probably a hundred broken screws before deciding to take the easy way out. I cut a tapered screw head and epoxied it into the broken screw holes. Then drilled new holes .Tapped them for a #10\ 24 thread machine screw worked great.good luck.

[Iansk]

I swear by Corrosion X. Hands down the best penetrant/anti-seize/rust inhibitor I've ever come across. I'll spritz it on a super rusty screw/bolt/nut then come back a few minutes later and I can almost always get it out without too much problem. In your case with the broken heads, I'd spray a bit in the hole then auto punch it a close to center as possible and proceed to drill it out with successively larger bits. It may actually screw itself out during one of the the bit steps.

[Mollysdad]

Screw extractor if possible. You drill a pilot hole in the broken shaft, then screw in a extractor. It's threaded backwards, so as you tighten the extractor, the screw backs out (in theory).
Stainless screws into aluminum are a problem because of electrolysis. Two dissimilar metals will cause ions to flow like a battery and weld the metals together.
Before you replace the screw, put a dab of "anti-sieze" on it.

My motto is always "Don't make it worse".

[woodfox45]

On my 2000 I can get at them from underneath the step opening .

[sgschwend]

Yes, work from the bottom.