Thread: Stainless Steel vs Carbon Steel

The magnetic properties of stainless depends on the micro structure. Austenetic stainless is non-magnetic, stainless that can maintain an edge is martensetic and is attracted to a magnet. It is due to the lattice structure. Most Austenetic stainless is still ~82% iron and yet is not attracted to a magnet at all.

Vic, Hi again buddy! Good to see you also. Good info there - additionally some of the austenitic stainless steels are commonly known as "3 series" i.e. 304ss etc. Some martensitic are commonly known as "4 series" stainless steels such as 440ss etc. as well as others such as 154cm etc. - if it's being used as a blade steel is almost always a martensitic.

There are also ferritic and duplex families of stainless steels.

Austenitic stainless steel is always either barely or not at all attracted to a magnet and not hardenable except by cold working (i.e. work hardening by rolling, rubbing, cold forging).

Martensitic stainless is hardenable by common heat treatment and is almost always attracted to a magnet. Ferritic stainless steels are attracted to a magnet but can't be heat treated.

Duplex stainless is basically a balance between the alloying ingredients that would normally make the steel austenitic or ferritic. Duplex stainless is the highest in pitting/corrosion resistance.