I recently made some linkages with carbon fiber rod and metal fittings using JB weld.this worked out to be a very good bond.I want to make some metal 4-40 rods with metal clevises.My soldering is questionable,and was wondering if JB weld would be a suitable alternative.

Yes, It would work just make sure to sand and clean the fitting before bonding. It's even stronger than solder. I have repaired numerous monster truck and heli parts with JB weld. Its also great for engine repairs due to the fact it's good to 600 degees.