broken plate bolt

[Ron Nossaman]

>A plate bolt 4 7/8 inch long and 3" in diameter sheered
>in two as I was screwing  it down. 

Three inches? My gosh man, you're lucky you weren't KILLED! For the sake of
dispelling this horrifying image in my head, I'm going to assume that is a
fickle fingered 3/8" typo. It happens, and I sure hope that's right.


>Does anybody make a habit of replacing old plate screws?

Yes, mostly, both perimeter lags and pinblock screws.  


>Any suggestions on getting it out? Anyone been there?
>I must find something that will drill it out and plug it, but
>it is very hard steel. Or I must plug the three inches above it
>and get a shorter bolt.
>
>                              Thanks
>                              Dave Renaud
>                              RPT

I've broken more old pinblock screws, mostly half of the head cracking off,
than perimeter lag screws, but I have a couple of possible approaches.
First is to run a 5/16" bit down the hole to dimple the top of the broken
screw. The 5/16 will stay toward the center of the hole without tearing it
up too badly. Then run a smaller bit, like 1/4" down into the screw using
the dimple as a centering device. That should heat the screw piece up
enough to dry the surrounding wood enough to loosen the screw enough to get
it out with an easy out. Enough? Option two is to drill down to the screw
with a 1/2" bit, then use the hole as a guide for a section of 1/2" OD
tubing with some teeth cut into the end to saw it out with a plug. Cut the
teeth backward and run the drill backward. You'll probably get lucky and it
will jam and back the screw out with minimal damage. Then plug the hole and
re-drill for a new screw.   

There probably wouldn't be any problem with a good plug and a shorter screw
either, for that matter, but I think I'd give it a go on the attempt anyway. 


Ron N