On Thu, 17 Feb 2005 17:47:15 -0600, Ben Jackson wrote:

On 2005-02-17, Ed Huntress wrote:
304 stainless steel.

How soft is that compared to stainless items I'm familiar with like
kitchen utensils or stainless nuts and bolts?

It's going to be somewhat softer. 304 can be hardened only by cold-work. A
stamped kitchen utensil picks up some hardness in stamping -- sometimes,
quite a lot. Cold-headed bolts are going to be harder than annealed 304.

Thanks. Having worked with copper in various hardnesses I wasn't sure
if annealed 304 was going to be almost butter soft like annealed copper
and require hardening before it could be used.
However, the real issue with 304 is not hardness, but toughness. It is
tough to machine, kinda like pure copper. It work hardens and wears
tools fast. And it also likes to stick to the cutting tool edge. So
enough tool pressure must be used to get a constant chip. If drilling
stops producing a chip the 304 will harden at the point of contact and
then dull the drill. Use plenty of cutting oil or coolant, slow enough
speeds, and enough tool pressure to get a constant chip. And don't
dwell with the cutting tool. It either must be cutting or it must be
removed from the work.
ERS