# Chuck key



## Mgdoug3 (Feb 7, 2021)

My new to me lathe only had one chuck key for the four jaw and I like have two for quick adjusting.  While typing this message, I'm 99% sure my other lathe had a 3/8 chuck key so I already had 2.  Oh well, now I have 3 and gave me some practice on the mill.  

I used the Pythagorean Theory to find all my measurements.  I started with 3/4" 1141 steel and turned it down to 0.53" in the lathe.  Went to the mill and took off 0.078", 90 degree turn and cut again. Repeated the process until it was square. I notched the other end and then welded on a handle.  

I got the square red hot with a torch and then used straight acetylene.  I heard that will case hardened it and figured I would try it.  The whole project didn't take long and I enjoy making my own tools.


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## Chipper5783 (Feb 7, 2021)

I don't know what it is about chuck keys - for the places I buy kit (the bottom end of the market), the chucks rarely come with the key.  I think I have made ~10 so far.  Chuck keys are often not some sort of a standard size, so to get'em just right the best solution is to make your own.  Also, I'm finding that I often want some sort of a feature (I put sliding handles in the ones that are on the dividing heads, I made a stubby for the collet chuck, I made a long one for my 12" mill table chuck, etc).  I new feature I have started (esp for the larger chuck keys) is to make the body hollow - but do it in such a way that it is very difficult to tell (make the plug of the same bar material).  Then watch a true shop guy pick it up, the smarter ones get a puzzled look because it clearly is steel, but it is lighter than it should be (I let them stew for a while ).


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## Mgdoug3 (Feb 7, 2021)

I made a set for my smaller lathe when I bought a 4 jaw for it.  I didn't have any key for it but I wanted to use it that day.  I found some 1/4 key stock and some pieces of all thread that I cut on the lathe laying around.  Welded them up and worked just fine. 

I always meant to make some new ones that weren't so crude but they still work just fine.  They also work on my piston ring compressor which is good because I lost the original.  I'm used to function over looks but with my growing tool collection I'm able to do both now. If I'm short on time, looks still come in second though.


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## Shotgun (Feb 11, 2021)

Put a hex on each end of the handle, and you can have a tool to tighten the carriage lock and. . .????. ..something else.

(I replaced my carriage lock bolt with a cap head screw for this reason).


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