We make a lot of parts out of maraging, but it is probably about $20 per
foot for that size range. Heat treat costs are high too so we would need a
big run. 440 stainless is another choice. Both can get to Rc 50 or more
without size changes but I would have to check how brittle it gets. Size
change during heat treat shouldn't be too big a deal anyway, the parts can
be centerless ground to the right diameter after HT fairly cheaply. Case
hardening other steels is an option as well. If Iremember though, the rotor
end is splined, that may be a complication.
Mark
----- Original Message -----
From: "Timothy F. Murphy" <timmurph@execpc.com>
To: "'FOT'" <fot@autox.team.net>
Sent: Tuesday, July 06, 2004 4:29 PM
Subject: Re: Pump Shafts
> Any thought to making the shafts out of maraging steel? This is a
> "space age" material or "super alloy" that has the very desirable
> property of being able to be heat treated at something like 400 degrees
> fahrenheit which virtually eliminates distortion or size changes. We
> used it at G&L to machine the "fingers" used for the tool holders, which
> had rather complex and precise geometry. After machining the heat
> treating left the parts as they were with the tolerances intact. The
> finished product was very tough with excellent mechanical properties.
> One problem - it's expensive stuff or it used to be. I did have some
> "prototype tools" made up by the R&D machinists which just happened to
> work really well on one or another of my cars. Great stuff.
>
> Just a thought,
> Tim
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