Although they are considered "New" - it does NOT mean "New Rods" are without defects. Per the American Petroleum Institute (API) Spec 11B, Section 7.2.4.2, the manufacturers are only required to inspect a very small percentage of your order - NOT 100% of it.
Therefore, to rule out a whole string of potential problem variables in your well(s) if just one small part fails, let PRO inspect 100% of your new rod order BEFORE they are put into use.