Douglas Frank wrote :
<snip>
>
> For future refrence, Rimmer's faxed me their specs for the shaft. I
> quote, without fully understanding:
>
> material ... BS.970:part3:212A42
> heat treat ... case harden 60-62 HRC, depth .75mm (pre-grinding)
> finish grind ... 4-6u c.l.a (that's 'u' for 'micro')
> tolerance (dia) ... 85 somethings
> max runout OAL ... .0015in
>
> If anyone can identify the US equivalent of that BS number, I'd
> appreciate it!
Douglas :
BS 970 is a standards document dealing with a wide variety of "wrought
steels". Part 3 is titled specifically
"Specification for Wrought Steels for Mechanical and Allied Engineering
Purposes - Part 3: Bright Bars for General Engineering Purposes "
So, the 212A42 is what you need to look up. From what I found on the web,
It's equivalent to EN-8DM, US G11410 and ASTM 1141, falls in the category
"Medium carbon and carbon manganese steels", and is described as "44 carbon
free cutting". (I assume "44 carbon" means 4.4% carbon by weight, but I'm
not sure.)
Randall
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