Pablo,

    Do you really need the same range of hardness values?...or will equivalent yield and tensile strength suffice?  Do you still want a precipitation hardened stainless steel that has been overaged?  Are you looking to get a new material that has equivalent mechanical properties but has better corrosion properties?  Are you looking for something cheaper?  As currently stated, your question is so open ended the list of possible materials that fit your requirements is huge.

For starters:
PH 13-8, 15-5, 15-7Mo, and 17-7 steels in just about every condition (except annealed) would suffice.

Maybe you could provide some more information about what you are looking for?

Andy

John,

the situation is that with currently using 17-4 as a threaded housing but its female connection is also 17-4  and there for durring operations at temps > 175 degree C galling of the threads is occuring. Ideally my prefered option is to use a new material i.e Monel k500, or other materials carrying equivalent yield and tensile strength values. Working conditions or for use in oil well enviroments at high temps.
I have also heard of a material called toughmet produced by bush wellman ltd. would this material surfice.

regards pablo