View Full Version : Acme nut

Mike Gibson
05-11-2006, 04:24 PM
I have modified the acme nut pictured to use as a die. I don't know the grade of metal it is made from and wanted to know what the hardening procedure is, assuming it can be hardened.


05-11-2006, 06:30 PM
I doubt it can be hardened but you could try to heat it to 1400 or so and quench in warm brine water. That will give a pretty hard quench so check it with a file. If it slides, you know it got hard to some extent. Put the nut in the kitchen oven at 400 degrees and let soak for an hour. That will put enough draw on it that it might cut without breaking - and yes, this is a complete SWAG since you don't know what type steel it's made from.

05-11-2006, 06:49 PM
It does look good though.:D

05-11-2006, 06:54 PM
You will find that threading acme with a die is very difficult. There is a lot of metal to remove in one pass. Why not single point thread whatever it is?

Tin Falcon
05-11-2006, 07:07 PM
Mike: as hw said a WG not knowing the material but a another shooting from the hip method is bringing it ito a nice red orange and dropping it in used oil, cooking type is not as toxic but motor oil also works. This does not get as hard as the brine method so you do not need to temper it in the oven.Try to find a good blacksmithing book to learn more about heat treating. An experienced smith can tell the temperature buy the color.

05-11-2006, 07:08 PM
Perhaps he is making a new lead screw for his lathe ,so he can thread on his lathe.;)

05-11-2006, 07:14 PM
Chances are it is screw stock, and does not have enough carbon to harden. KasenIt or other case hardening compounds can be used to harden low carbon steel enough for chasing threads.

If possible, singlepoint the threads and use the die to clean them up to size. It is very difficult to thread Acme with a die.

kap pullen
05-11-2006, 07:36 PM
If you do manage to cut threads, they will likely be oversize because nuts are made oversize to be a loose fit on the thread.
Good luck,

Mike Gibson
05-11-2006, 08:00 PM
I should have included that it would be used to clean up previously cut threads.