Rudy, and all others in this one...
If there is a welding shop nearby, consider copper-clad welding rod. It IS soft iron, NOT hardened steel, but is plenty stiff enough for pushrods for up to .35-.40 models. For larger engines, some other approach -arrow shafts of fibreglas or even aluminum, tipped with adapters to fit control horns- makes sense.
Good dikes can cut this stuff. It is "tweakable." You can buy a pound for under $5.
The softer, unhardened, stuff can be bent tighter without stress fracture. ...and easier.
As with building a model, you can use MORE of a "weaker" material, that is lighter (such as balsa v ply or hardwood), for the same strength. Weight doesn't change much, here, but you can use 3/32 instead of 1/16 for the same effect. Stiffness is helped more by 'fairleads' than material strength, anyway...