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Machining cold forged aluminum part.

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Machining cold forged aluminum part.

Old 11-12-21, 04:58 PM
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bark_eater 
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Machining cold forged aluminum part.

I figured some one here might know. I was wondering if it was practical to machine a cold forged component? Or are there additional stresses in a cold forged item that will cause warpage or weakness from cutting the "grain"?

The simplified example is If I have 2 cold forged bars. One is 5/16" and the other is 1/4" I would like to mill the 5/16" bar to 1/4" by removing 1/16" from one side. Will I end up with 2 bars with the same "strength", or will the modified bar be "weaker" or prone to warping?

Last edited by bark_eater; 11-12-21 at 06:28 PM.
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Old 11-12-21, 08:30 PM
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unterhausen
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If I had a forged flat bar I would machine it in stages because some stresses are likely to be released during machining.

What exactly do you want to do?
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Old 11-12-21, 08:55 PM
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I'd like to thin and reshape a crank arm. I've got a Shimano FC-6207 left crank. It looks to me that the Dura Ace FC-7400 is made from the same forging and is machined down a bit and fully polished. I'd like to thin the FC-6207 left arms front face and contour the back to match a Ritchey Logic right side. I'd be using hand files and abrasives.
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Old 11-13-21, 09:03 AM
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I imagine you would be okay. Like any aluminum under cyclic loading, you should make sure your polishing is good.
I went looking for drillium examples of that crank and failed to find any, which surprised me a little.
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