Date: Mon, 9 Dec 1996 02:15:02 -0800 (PST)
From: Mike West <mwest@cdsnet.net>
Subject: AS21 vs AS41 cases , hard numbers

 I don't think this got back to the type2 list so I'm taking the
liberty in hopes there are a few who would like the data.

 Thanks to Bill Claspy on the VINTAGVW List.
- - - - - - - - - -- - - - - -  - -

Hello!

Just happen to be a librarian at an engineering library, so this is in
response to Mike West's request for info on the case alloys used.  His
guess of 20-30% aluminum is just a little off :-) (his text follows my
numbers)

>From the ASM Metals Handbook, V.2, 10th edition, 1990

Room Temperature properties:

AS21            1.7% Al
                .4% Mn
                1.1% Si
                240 MPa Tensile Strength
                130 MPa Tensile Yield Strength
                130 MPa Compressive Yield Strength

AS41A           4.3% Al
                .35% Mn
                1.0% Si
                220 MPa Tensile Strength
                150 MPa Tensile Yield Strength
                150 MPa Compressive Yield Strength

"AS41A has creep strength much superior to that of AZ91D or AM60B alloys at
temperatures up to 175C (350F)... AS21 alloy exhibits even better creep
strength than AS41A.  However, AS21 has lower room-temperature tensile and
yield strengths, and it is somewhat more difficult to cast."

Hope this helps!  And if anyone deems it important enough to stick these
numbers in a FAQ, feel free.

Bill  (William Claspy)
- - - - - - - - - 

Mike West sez:

>  What I would like to see is the "Spec" sheets on the 2 alloys.

> Isn't there one Mechanical Engineer out there with a "Library" who
>can look this stuff up?
>
> Oh, I checked with ASTM and they claim only to "list" an "AS41".
>
> Of course they won't "give" me the "specs"  but will sell me the the
>"spec sheet".
>
>  west