In article ,
Ned Simmons wrote:

On 30 Aug 2011 01:55:38 GMT, "DoN. Nichols"
wrote:

On 2011-08-29, Tim Wescott wrote:


I'm basically looking for a steel that'll be suitable for model airplane
crank shafts. The advice that I get from the hobby builders of model
airplane engines is "use 12L14 and don't crash". I'm not going to
discount this -- but it'd be nice to be able to do something on par with
what I buy at the store. So, basically, something that's easy to
machine, but that'll harden up to something between a grade 5 bolt and a
grade 8 bolt.

I don't think that you will find both "easy to machine" and
Grade 5 to Grade 8 bolt hardness in the same metal.


"Stressproof" (a modified 1144) has a yield around 100ksi, about
halfway between grade 5 and grade 8 screws. It isn't as easy to
machine as 12L14, but it's not bad considering its strength. This
table rates it about the same as 1018, which seems about right.
http://www.carbidedepot.com/formulas-machinability.htm

McMaster carries generic Stressproof on p. 3633.

I made my replacement vertical mill drawbar out of 1144 stressproof. It
was easy to machine on the Clausing 5914, although the machining forces
were about double those of 1018.

Joe Gwinn