This is the process that stainless steel(SUS) disc is bonded onto aluminum bottom by heavy duty hydraulic press machine with its stylish appearance.
This kind of bottom has been developed to improve some problems of thermal spray IH bottom (it sometimes scratches ceramic board of induction cooktop and a few induction cooktops are not working with small sized thermal spray IH bottom.
2 kinds of bottoms with SUS disc are available as following photos.
1) Coated bottom and 2) SUS disc exposed bottom
However, we would recommend coated bottom to prevent rust and discoloration for long time. (Arc thermal spray is better in terms of induction efficiency . )