My neighbor, aware of my engineering interests and workshop, has asked for some assistance with one of his old tractors. It has adjustable width front axle as shown in the photo atthough it's not exactly the same as the one shown.
He=92s managed to remove 3 of the 3/4" bolts but the 4th is seized solid (in the row of holes across the front axle beam). He=92s beaten the end so much that it mushroomed and he then ground it back to flush before trying to drill it through (off centre and out of alignment). He broke a 12mm drill off in the hole but managed to remove the piece. He=92s also tried using a large set of Stilsons on the bolt head with a scaffold bar for extra leverage but only managed to begin to destroy the bolt head. At that point I was asked for advice.
I've tried continuing with the drilling with several more broken drills to show for it when they bite/grab at the bottom of the hole. I don=92t think a hand held machine offers enough control. We=92re going to try an electromagnetic base drill when the local hire shop gets theirs back from a site.
I've also tried hitting a length of metal set in the hole but the rust has had a long time to build up a really good grip.
Other people have said that heating should help but I=92m not sure how. All the parts involved are almost certainly steel and hence will expand at the same rate. I can only think that lots of heat (oxy/ acetylene to a dull red heat) might change the rust to something weaker so that a few good hammer blows will shift it.
So, any and all suggestions welcome.