Made a longer chuck key

[G-ManBart]

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]

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]

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