# Lathe Chuck Material



## ddickey (Jul 25, 2017)

What is the difference between a cast iron chuck and forged steel? I know cast iron has better vibration absorbing qualities but why then are the steel chucks more desirable?


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## mksj (Jul 25, 2017)

Forged steel is stronger and can withstand higher centrifugal force/RPM. Semi-Steel is considered a lower grade steel, may be a combination of lower grade steel/cast iron which may often contain scrap iron. I would assume that for chuck applications that semi-steel would need to have some uniformity as to the final mixture percentages. The vibration absorption ability would not be a factor in this application. Forged steel chucks can be quite a bit more expensive, but may be warranted is you need a higher speed rated chuck. So something like an 8" chuck is usually rated to 2000RPM maximum speed in semi-steel and 2500RPM for forged steel.


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## ddickey (Jul 25, 2017)

Thanks,
I was looking at a Rohm cast iron chuck. Max rpm was 1700. I was surprised at how much cheaper they are, ~$500 compared to $2000 for steel.


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## wrmiller (Jul 25, 2017)

ddickey said:


> Thanks,
> I was looking at a Rohm cast iron chuck. Max rpm was 1700. I was surprised at how much cheaper they are, ~$500 compared to $2000 for steel.



If you have an older/slower lathe, cast iron or semi-steel works fine. I would recommend forged for new(er) lathes that can spin upwards of 2000 rpm. IMO of course.


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## benmychree (Aug 3, 2017)

I think that longevity or accurate service life is also a factor in choosing between cast iron/ductile iron and steel chuck bodies; if one is buying for the long haul and heavy work, steel is the way to go.  I agree with the writer above regarding older slower lathes, and especially for hobby use where use is limited, as our productive years may also be limited, there is no sense in going steel.  Lower RPM machines just take a little longer to accomplish smaller diameter work.


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