We use V2A stainless steel (1.4301). The advantages of stainless steel at a glance:
The surfaces are glass bead blasted (e.g. stainless steel slides, sliding rods), stained (e.g. fittings, small parts) or electro-polished (e.g. GFRP-slide with VA lining). The purely metallic, and thus slow-reacting surface prevents discolouration and formation of deposits to ensure an attractive and, depending on polishing degree, brilliant look.