# Cast iron thread repair



## murraym (Jul 31, 2022)

I have an old cast iron meat grinder and i am looking to attempt to repair some worn out threads. I think i want to turn the old threads off and braze a new cast iron sleeve on and thread it.  I am unsure of the type of cast iron that the part is.  Does it matter the type of cast iron I use for the repair? Also I would be looking to buy a drop from somewhere.  Any ideas where I should look? Thank you all in advance for your replies!


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## sdelivery (Jul 31, 2022)

What does the nut look like?
I would be more inclined to make a new undersized nut.


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## murraym (Jul 31, 2022)

I don't have any pics of the nut but it is about 4" in diameter,  cast iron with 4 handles around the outside.  The threads in the nut are not nearly as worn. The picture of these threads maybe don't clearly represent how much wear there is. The nut may need some work as well,  but my plan is to repair these first being they are the worst shape.


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## Chewy (Jul 31, 2022)

Don't know if this helps, but I just saw a video where the guy brazes the missing/worn thread on the shaft then picks up the thread and re-cuts the bronze.  Don't see why it wouldn't work here.


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## murraym (Jul 31, 2022)

Chewy said:


> Don't know if this helps, but I just saw a video where the guy brazes the missing/worn thread on the shaft then picks up the thread and re-cuts the bronze.  Don't see why it wouldn't work here.


That is a good idea.  I just may do that.  Why cant i think of that???? Thank you


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## Chewy (Jul 31, 2022)

Don't feel bad   I have been doing repair work for many years and brazed a lot of cast iron in my time.  That was the first time I saw somebody braze up a square tooth shaft and machine it.  Worked pretty good.


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## markba633csi (Jul 31, 2022)

Adding braze metal and re-cutting thread is a good method- However you might need a better way of chucking up the part than that shown.
Perhaps fashion some type of dummy hardwood mandrel and force it into the threaded end so that it faces the headstock- use a 4-jaw chuck
Not sure if the sidearm would be in the way...
-Mark


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## murraym (Jul 31, 2022)

markba633csi said:


> Adding braze metal and re-cutting thread is a good method- However you might need a better way of chucking up the part than that shown.
> Perhaps fashion some type of dummy hardwood mandrel and force it into the threaded end so that it faces the headstock- use a 4-jaw chuck
> Not sure if the sidearm would be in the way...
> -Mark


I have a bullnose live center that i was going to use. It will need to come back out for brazing though. Ill look at it. Thank you


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## markba633csi (Jul 31, 2022)

Perfect- why didn't I think of that?


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