This is a lead-free, argon gas welding seam from the construction processes. We use a premium type 304, grade 18/8 stainless steel with raw materials testing.
The rolled steel sheet is formed into a tube and welded using lead-free argon gas. The stainless tubes then go through a series of hydraulic expansion and heat-treating processes to create specific model shapes. Finishing of the inner container is done with a combination of dolomitic sand-blasting and an electrolytic charge. Unlike aluminium drinking containers, stainless steel does not require a lacquer coating on the inner surface, which often contain BPA.