The stainless steel layer in the Falk Culinair bimetal is only 0.2mm (200 microns) thick enough to prevent the contents of the pan reacting with the copper body without materially effecting the superior conductivity and distribution of heat in copper.  It is virtually indestructible, and unlike tin, requires no maintenance.

The stainless steel is “18/8” grade.  The number relates to the chromium and nickel contents of the steel, which are 18% chromium and 8% nickel respectively.

“18/8” is the most commonly used stainless steel.   This steel is known as 1.4301 in the European BS EN 10088 standard, or '304' (in the American AISI grade designation system).

It is an 'austenitic' type of stainless steel which is a high quality, sanitary, food grade stainless steel used in numerous food, dairy, brewing, hospital and sanitation applications all over the world.

The exact composition is:

Please note, there is no significant difference in the mechanical properties, or strength, between 18/8 and 18/10 stainless steels.  The 18/10 may be very slightly more ductile (i.e., slightly more able to bend without fracturing) than 18/8, but the difference is so minimal as to be completely inconsequential for our application.