Posted by Chriscase [107.201.31.32] on Thursday, January 30, 2014 at 09:16:56 :
In Reply to: Re: MU2 Winch Question... posted by Kaegi [98.247.164.246] on Thursday, January 30, 2014 at 02:37:08 :
Many of the castings on our trucks are cast iron that is treated after casting. It gets baked at 850 degrees fro a day or so. Which changes the grain structure, making it five times stronger. Parts get slightly flexible, and can crack rather than shatter.
I use the drill chip test to confirm iron metalurgy. Cast iron makes grains, about like sugar. Steel makes long curly shreds. Maleable makes a mix of grains and little shreds, like caraway seeds mixed in with the sugar. No need to drill deep, point of a 3/16" bit ought to do. Drill where it won't show, or start a crack. On this part, I would drill on the end face between the bolt holes.
Other guys do a spark test- grind it and watch the sparks for color, brightness, shape of streak. But I need a chart for that. It's on the net somewhere.
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