Surgical steel and part production

Question

Steels 316L, 420, 17-4PH and 316LVM are often chosen for medical products and labelled as "surgical grade".

I am curious as to how these types of steel are used for the production of common medical tools, for example ball-tipped tools such as "dental ball burnishers". Are these cast? If so, I suppose the parting line would be visible along the tool. Or alternatively, could the steel ball, rod and handle be manufactured separately and then welded? I guess this doesn't make much economic sense. As a third approach, I have noticed piercing parts being manufacture by screwing threaded steel balls on threaded rods. Again more labour intensive than casting, but less setup costs (no molds needed).

Answer 1

When I was a boy; We made a eight shapes ( as I remember) of parts like that for Ritter. They were produced by investment casting using 17 - 4 PH. There was a die witness line that carried over from the plastic pattern; it was polished away during tumble polishing. Medical equipment also uses 440 A, B and C for cutting tools. Vitalium may still have some use also.

Answer 2

I suspect that these are stamped to a rough blank and then the ball and tapered stem is finished with some sort of axial grinding process, probably by hand with the assistance of a jig.

Ball ends can be machined fairly easily with a rotating jig and it would be much easier to form the ball in one piece with the stem then try to weld it on.

the kink on the end if probably just bent near the end of the process.

It actually looks like something whcih was prototypes on a lathe but the knurling and shoulder radius have a lack or radial symmetry whcih suggest a stamping.