[TowerTalk] Mast slippage

[Wes]

In my youth I spent some time working in the automotive machine shop that my dad 
ran.  Disk brakes were unheard of then, so everything was drums.  (I'm dating 
myself).. In addition to the asbestos dust that we breathed while machining the 
drums we often ran into "hard spots" that totally resisted the carbide cutting 
tool and required the use of the grinding attachment.

Speaking of low-grade iron, most Ford crankshafts were cast iron, while the 
other guys were mostly using forgings.  I took a 272-292-312 series Ford crank 
out of the "hot tank" degreaser one day (a nearly boiling tank of lye) and stood 
it on its flange to hose it off before grinding it.  When I hit it with the 
spray it tottered and fell over.  When it hit the floor it promptly broke in 
half.  The reason was that there was a harden ball bearing ball cast into the 
shaft.  This was from an engine that had been run.

Wes  N7WS


On 7/29/2020 3:03 PM, Charles Gallo wrote:
> Cast Iron is “interesting”
> If you get good grade cast iron, it machines like butter
> If it is cooled rapidly, you get what they call chilled cast iron, which can be amazingly hard, like you either must aneal it or use a grinder (I had a casting I could not true up short of using a surface grinder)
> In addition to the above, low grade stuff can be full of very very hard scrap (and is more likely to be chilled)
>
> --
> 73 de KG2V
> Charlie