Before my answer, I need to point out what IMHO is the most significant difference between fits and tolerances.
- fits usually refer to a mating of two components (an assembly).
In engineering terms, the "fit" is the clearance between two mating parts, and the size of this clearance determines whether the parts can, at one end of the spectrum, move or rotate independently from each other or, at the other end, are temporarily or permanently joined together. (source wikipedia).
- Torelance can refer to many things, but more usually refers to the permissible limit or limits of variation in a physical dimension.
Metallic bars and HSS.
In the above context, when you buy a metallic bar/HSS section there is usually no fitbe no fit. E.g. only tolerances of the diameter of the bar, or other types of tolerances (orientation, location, form etc), are relevant.
So (to my mind) when you buy a product a steel bar from a shop/vendor you accept the tolerances that this particular batch has. If you can order a much larger quantity (economies of scale), you can contact directly the manufacturer and have them produce the product in your specific tolerances. So in that respect they are manufactured.
There is a certain class of products (again in my mind - this is very much an opinionated answer), that I call interchangeable. In that category fall e.g. bolts or bearings. It is very common products (of high engineering design, competence and expertise) that on their own don't perform much, but are essential parts of other machines (most if not all).
This particular type of products, are so common and yet specialized that you can buy them into classes of tolerances. e.g. SKF has for its bearings a class tolerance Normal, P6, P5 and it goes to P4 and below in what it calls "super-precision" bearings. Similar to bolts.
My point is that in that particular context (interchangeable products) it is possible to buy different classes of precision/tolerances (and not just manufacture them)