On Thu, 19 Sep 2013 07:02:38 -0500, Karl Townsend
wrote:

On Thu, 19 Sep 2013 07:34:05 -0400, Ed Huntress
wrote:

On Thu, 19 Sep 2013 05:18:44 -0500, Karl Townsend
wrote:

I just bought a rifling button so I can make my own 9mm barrels
http://tinyurl.com/kdn8mzg

You need a five ton press to push this button down a barrel to form
the rifling. OK, what would be the highest strength steel i can get
for the pusher. I looked for HSS and couldn't find anything long
enough. looked for already hardened drill rod. It must be out there
but no joy so far.

My first barrels will be 12", want to do 16" in the future.

Karl

If the bar can be 0.35" diameter, you're looking at less than 0.1 ^2
in. of area. Yikes. You need 100 ksi compressive yield strength in the
bar to handle the full five tons.

HSS is no stronger than many high-strength alloys. Pre-hardened,
ground drill rod is available.

Another possibility is the bar stock from Timken and others, intended
for making roller bearings. That stuff runs upward of 180 ksi tensile.
In most steels, compressive strength is close to, and directly related
to, tensile strength. And tensile specs are easier to find than
compression-strength specs.

Music wire in these dimensions is not nearly as strong as the thinner
types.

Good luck!

Any idea where to order the timken stuff?

You need a small steel supplier or a steel service center that will
sell you a little piece. They don't want to, but sometimes they're
sympathetic.

If it were me, I'd look into Timken's list of suppliers:

http://www.timken.com/en-us/purchase/Pages/default.aspx

....and get on the phone with them. Tell them frankly that you need one
piece. They may know of a supplier who will do it for you.

Or you could become a manufacturing magazine editor and ask for a
sample. d8-)

Timken bearing steel is the high-end solution. Really, 0-1 is more
than enough. It's typically delivered in one of three conditions:
annealed, as-rolled, and hardened. As-rolled is Rc 50. Its compressive
yield strength is 196,000 psi -- 'way more than you need.

That's probably the easiest one to get, because small steel suppliers,
and even online hobby suppliers and *maybe* Brownell's, deal in
onesies and twosies of that material.


What about the carbide listed in the next post?

Crack!...goes an expensive piece of carbide. It's not tough enough for
futzing around with a small-shop press.

Again, good luck. You shouldn't have trouble finding a piece of steel
that's strong enough, although ordinary mild steel might turn to mush
under that much compression. Go for a good, common alloy steel, or
maybe a hardened piece of 1070 or1090 carbon steel, and you should be
able to do it. At that small diameter, even cold-rolled high-carbon
should do it. Cold-rolling hardens small diameters much more than
larger ones.

(I always thought they pulled, rather than pushed, rifling buttons,
but maybe that's just the gun manufacturers.)

--
Ed Huntress


Karl