As mentioned in the subject, I'm looking for steel suitable to be used to make an Olympic barbell, 2.2m long and 28mm in diameter. I'm torn between chrome-moly steel and spring steel. Again I'm not a metallurgist and know very little about these things. The bar will be at least 190000 psi tensile strength with 170000 psi yield strength. I'm also looking for decent machining characteristics so that I can put a knurl on it and cut grooves to attach sleeves.

Here are some steels I've thought about

SAE 4340 (Heat treated to the required Tensile strength)
SAE 4140
EN 47??

Thanks