"Denis Marier" wrote in message
...

One point is that the two locking (Tommy) bars are made of cold rolled
steel. They do not bend but the edge at the end of the bars will wear out
a
little after a year of use. I would replace them with the right size
drill
rod.

Just grind the ends back. The softer, easier to replace steel is a better
bet than the hard stuff, which would distort the holes in the chuck. If you
don't want to grind, just get some cold-rolled rod of appropriate size to
serve as tightener and "sacrificial" metal.