Yes, stainless steel rod and round bar are often used interchangeably. This is because most of the differences are superficial. 

Round Bar vs. Stainless Steel Rod

Stainless steel rod can be square, rectangular, or hexagonal. Stainless steel rod is generally finer than round bars, with diameters ranging from 1/16 inch to 1 inch. Stainless steel rod is also more flexible and malleable than round bars, making them ideal for intricate designs and applications requiring bending. Stainless steel rod can have a varied finish.

Round bars, in contrast, usually have a smoother surface finish. This smoother finish is essential for precision applications. Round bars also have a higher carbon content than stainless steel rod, making round bars stronger but more brittle.

The Metal Company offers round bars in both metric and imperial sizing.