On Tue, 05 May 2015 11:28:11 -0700, Bob Gentry wrote:

On Tue, 05 May 2015 12:43:18 -0400, Ed Huntress
wrote:

snip

Mild steel will be as stiff and rigid as any steel -- they all have
the same stiffness -- but it won't be particularly strong. However,
you're not likely to approach the strength limitations of mild steel
or any other steel in this application. If you did, the toolholder
would be springing so much you couldn't use it anyway.

Ed
Thanks for the insight!

I've never used 12L14 and I've heard it is easier to cut and gives a
nice finish. Would you see any problems with that in this application
(just to try something new) ?

Bob
rgentryatozdotnet

It's very nice to machine. No problem, in general.

I haven't looked at a shaper toolholder for a long time -- probably
never for an insert type -- but the only general weakness of mild
steel for tooling is in threads for clamp screws. If there's enough
length and meat in there, you shouldn't notice any difference versus a
piece of D2 tool steel.

Brit hobby magazines used to make this point often: Unless you intend
to beat the crap out of your tools, there aren't a lot of
applications, except for the cutting edges themselves, where mild
steel won't serve just as well as an expensive tool steel.

The stiffnesses of different grades of steel all fall within a very
narrow range. Stainless is about 7% - 10% lower; otherwise, there
isn't much to choose in terms of stiffness.

--
Ed Huntress