Thread: Is your 4140 CDA magnetic?

It seems the smaller sizes of 4140 cold drawn annealed that I buy are magnetized. If I saw a piece of 1 1/4" it takes all the chips from the blade along when it is removed. Smaller is as bad, larger such as 3" don't bother as much. The 1018 of any size does not do this. Anyone got an answer?

Ed.

Anyone got an answer?

That is why they sell degaussing coils

We have seen the same thing with .250" flat bar. We were only waterjet cutting it, so it was not an issue though I did demagnetize the parts once cut.

I have demagnetized parts like this on an electromagnetic surface grinder chuck in the past. (They usually have built-in demagnetizers). I believe this is a pretty common occurrence on 4140.