about 4140 hrc 45-50

[dev4deep]

Hi everybody
I have one 4140 45-50rc job. It’s “L” shape with 0.75” x 2.37”x7.0”. It has one 0.5 p.f. Blind hole on 7.0” side with depth 6.7” and top of the “L” shape I have 0.2” lip with horizontal & vertical full radius and there is other three tap holes. I’m thinking to do from 4140 annealed and then after does heat treat but my question is after h.t there is any chance to change dimension? This is first time I” m dealing with 45-50rc any suggestion it’s useful

[Janos]

I am in the process of doing a job out of the same material but only having to go to 35-40rc. The engineers had made up a Pre-Heat treat and a Post Heat treat machining prints. They left from .010 to .050 material to remove for finishing. So would say that it would move some.
On this job they got out their 4 place pencil and scribbled all over it.
If you need any more info feel free to ask, I'll tell you what I know.

Janos

[msomerville]

In my experience with 4140 you will notice some distortion in your dimensions.

[ctate2000]

It will move. Plan to finish any dimension clsoer than .005 after heat treat. Good news is that 45-50 will cut readily with carbide tooling.