What alloy to use for a crankshaft?

[JPar]

The crankshaft in my Galloway 5 HP 1/3 scale engine has a few issues.  This is a fabricated crank, and the main problem is that one of the shafts is a loose fit in its web.  It's held in place by a pin, but it should have been silver brazed as well. I've decided to make a new one, rather than try to repair it. The shaft is 0.625" (5/8) in diameter, the stroke is 3.375", and the overall length is 10.5 inches.

What would be the best alloy to use? The drawing just says "CRS". It needs to be silver-solderable, as well as
adequate strength, decent machinability, etc.

All suggestions appreciated.

Thanks,
    John

[Jasonb]

The CRS applies to the webs, I would use EN3 or EN32B bright flat bar.

For the shafts I have used both silver steel (drill rod) and PGMS - Precision Ground Mild Steel for crank shafts. I think I used the Silver Steel option on my one.

[JPar]

Thanks for the reply.  I've ordered some material (1018 and drill rod) and am awaiting its arrival.
John