A wire and flux I got from Homedepot. It was cheap, about 3$ and it said it was for hobby works. On the
back of the package it said it was tin and silver, but I can't remember the numbers. Melts at about 420 F, and strenght is about 18000 psi (according to the package). I did however, prepared the metal in an elaborate way.
The bolt body was drilled in steps, the part opposed to the bolt handle is 6 mm in diameter, the part
facing the bolt handle was 8 mm, and then the handle was shaped like that, the first 5 mm of it's length
(inserted in the bolt body) were 6mm in diameter, the rest was 8mm. So the part of the handle inserted in
the hole actually has two different diameters. I got the bolt handle in a drill machine and used a file to
have it round, from 8 mm to 6 mm (actually the tools were in inches, 5/16 and less, but I use metric calipers and inches still confuse me) I cut deep scratches inside the hole and on the bolt handle, and
the handle was inserted a litle forced. I also drilled a deep hole in the bolt handle ball, and the
corresponding end of the handle was cut and scratched. Cleaned everything with wire brush and alcohol. All holes were also touched a little with a large diameter drill, so that the edges would be a hint conical, this gave more surface for the melted alloy. And used a lot of flux. when finished with the boltbody-bolt handle welding, the other end of the handle was inserted in the ball and welded.
It looks good and I dropped it and hit it, it's strong. Both ends of the bolt handle (actually just a 10 cent
5/16 bolt from Homedepot) were cut in crosses and spirals (more surface for welding melted alloy) before being inserted in the holes (one end in the bolt body the other in the ball) and welded. Sorry for my horrible technical English.
Thanks.