Re: [CAD_CAM_EDM_DRO] Re: General Tool Life Question

doug98105 wrote:

> GM4T,
>
> In general, their shelf life is very good.
>
> But, if you intend to tap holes don't fool around with carbon steel
> taps. High speed taps aren't that much more expensive so why take
> the increased chance of poor hole quality or tap breakage by using
> junk?
>
> BTW, do any USA companies still make carbon steel taps?

Gosh, I'm sorry - I should have caught that when I posted a reply
earlier! Yes, I agree totally with the above. I use HSS at a minimum.
The only possible carbon steel taps I have came in a set from India,
I think. They were black. They were either so soft they would twist
like twist drills in brass and aluminum, or so hard they would just
crumble to dust in mild steel. Obviously, total lack of quality control.
I guess they heated them in a forge or flame until red hot and then
threw them in a bucket of oil.

The bright, shiny taps with overall ground finish, not rolled and hardened,
are of vastly better quality then the garbage they sell in the local
hardware store. I won't buy ANY cutting tools there unless in a REAL
big pinch.

Jon