# Made a longer chuck key



## Janderso (Jan 30, 2021)

I’ve been wanting to do this for quire some time. To be honest, I wasn’t sure how to cut the square.
Thanks to YouTube and my learning curve reaching a point where tasks like this seem rather simple.
And, it was a simple project.
Question, I used 4140 for this project.
Should I harden the key at the square section?
I’m thinking yes.
What say you?

The pics, I centered the handle rod.
I love these spiral flute quality taps!
I found 4140 a bit difficult to machine until I found the right, sharp positive rake insert and I run them much faster than I use to.
I’m not hesitant to machine it anymore.
The key fits perfect.


----------



## DavidR8 (Jan 30, 2021)

Nice work Jeff!
I think I would HT the end of you can but I'm far from an expert.


----------



## benmychree (Jan 30, 2021)

If you used 4140 HT, it is good enough as is.


----------



## Janderso (Jan 30, 2021)

benmychree said:


> If you used 4140 HT, it is good enough as is.


Good to hear John,
I really didn’t want to go there. I could do a ghetto heat and dunk and try to bring back to straw but, it’s a guessing game.


----------



## Janderso (Jan 30, 2021)

benmychree said:


> If you used 4140 HT, it is good enough as is.


John,
I looked up the order from McMaster back in April.
It’s annealed multipurpose 4140 steel rod.
Tough enough?


----------



## benmychree (Jan 30, 2021)

Not really, for the long haul, but good enough for light to medium use.  If I did a qu& Dirty HT, the draw would be closer to blue than straw.


----------



## benmychree (Jan 30, 2021)

There is no serious reason to avoid 4140 HT, it is fairly easy to machine, not so hard as to be difficult to machine.


----------



## projectnut (Jan 31, 2021)

I've made a number of them over the years, mostly from 1018, and a few were 4140.  I don't have a way to heat treat them so none lasted more than a few years at best.  Those made from 1018 lasted less than a year, but that was expected. Oddly enough it's the smaller ones (3/8" & 1/2") that wore out first.  Maybe I was just heavy handed when using them, but the T handle was less than 4" across, and I never used a cheater bar or more than 1 hand to tighten them.

A few years ago I picked up several commercially made ones from a used machine tool dealer for $4.00 a piece.  I have no idea what brands they are, but they seem to work well and aren't wearing out.


----------



## rwm (Jan 31, 2021)

I have made several and have not hardened them. Someone (here?) advised me not to, so that the key would wear rather than the socket. They have held up fine for light use. I have never checked a factory key for hardness? Does any one know how hard they are?
Robert


----------



## Janderso (Jan 31, 2021)

Well,
Right, wrong or whatever, I performed my ghetto DIY heat treat and temper on this annealed 4140.
Time will tell. Based on previous experience, it should be fine.
John York mentioned more of a blue vs. straw. I did the best I could.
When John speaks, I listen.


----------



## G-ManBart (Jan 31, 2021)

Janderso said:


> Well,
> Right, wrong or whatever, I performed my ghetto DIY heat treat and temper on this annealed 4140.
> Time will tell. Based on previous experience, it should be fine.
> John York mentioned more of a blue vs. straw. I did the best I could.
> When John speaks, I listen.


That should be more than fine.  4140 doesn't have that much carbon (.4% give or take) so it doesn't get super hard to start with.  It maxes out around 59 Rockwell, and the color you got probably brought it down to something like 50 Rockwell which is going to be hard, but not brittle. 

Some of the less expensive anvils (still fairly expensive!) are now made right around that hardness...it's too soft for my taste, but they make them that way so the edges don't chip easily when used by inexperienced people.

BTW, nicely done!  That's a good motivator for me...I need a better chuck key for the 3-jaw on my Sheldon.


----------



## benmychree (Jan 31, 2021)

rwm said:


> I have made several and have not hardened them. Someone (here?) advised me not to, so that the key would wear rather than the socket. They have held up fine for light use. I have never checked a factory key for hardness? Does any one know how hard they are?
> Robert


I'm thinking that a worn key would cause more wear on the socket due to poor bearing in the square (or hex).


----------



## Dabbler (Jan 31, 2021)

Nice fabrication!  The heat treat you did looks very good.


----------

