Karl
how much should I let it cool down, so I can hold it in my hand or until the color is gone?
Dana

Room temp.

What is it - exactly  - you are trying to soften?

A piece of 5160 from a leafspring
thanks for the help

I realize that - I read the thread.
Are you trying to make the blade or the tang more "friendly"?
Are you filing or grinding?
Why do you want it more machinable?

Karl
I am trying to get the blade soft, so I can flat grind it. the reason I'm asking was, after I forged it, it was so hard that a new 80 grit belt would not hardly touch it. I annealed it two times today and waiting for it to cool to see if it's soft.
Before I annealed it I took all the scale off like Lin said. I'm going back in the shop and will repost what I find out
Dana

There's really not much difference in grinding hard or soft steel at the 80 grit level.
You should hardly be able to tell the difference.
Scale was probably your problem.
We really need to be more careful with this term "annealing", especially when we use it in reference to steel with more than .84% carbon, as well as less than .84% carbon.
As well, slow cooling from above critical and below critical.
That right there is four entirely different animals.
And what are we "annealing"?
Hardened martensite or pearlite?
There's a whole heck of a lot more to it than getting a piece of steel hot and cooling it off.
If not done from the right steel phase at the right rate and temp, grain growth can just destroy all of your time and effort.
There are no short-cuts in this stuff - if you want to do it right.

Ok I think I can put this thread to rest.
It's soft, it was probley soft but the scale was hard.
Thanks for all the help from everyone and I hope this helps others
Dana