431 stainless steel magnetic properties

[vono]

I have a part that I need to make and the design calls for 431 stainless steel because of its magnetic properties. This part will hold another mart that is magnetic. I am having a hard time finding 431 stainless. Would 409 stainless steel work for this?
Are all ferritic stainless steels ( 409, 430 and 439) have the same magnetic holding force?
If I compare Ferritic ss ( 409, 430 and 439) and martensitic ss ( 410, 420, 440 ) will they all have the same holding force?


Thanks,
Jay