STAINLESS STEEL SOCKET DRIVE METRIC MACHINE SCREWS

316-grade stainless steel metric machine screws with socket drives (also known as Allen or hex socket drives) are high-strength fasteners designed for maximum corrosion resistance in marine, coastal, and chemical environments. 

Socket Head Cap Screws: These feature a cylindrical head that can be plain or knurled. They are ideal for applications with limited space and high strength requirements.
Button Head Socket Screws: These have a low-profile, rounded head used for a sleek, finished appearance or light fastening where a wider bearing surface is needed.
Countersunk Head Socket Screws: Designed to sit flush with the material surface, these are commonly used when the screw must be concealed or partially hidden. 

Material Specifications
According to Bolt & Nut Australia and Scrooz, 316-grade (A4-70) stainless steel provides "ultimate" corrosion protection compared to standard 304 grade. 
Magnetic Properties: While largely non-magnetic, they may show slight magnetism due to work-hardening during manufacturing.
Galling Risk: Excessive pressure during tightening can cause "galling" (thread seizing). Experts recommend slow tightening and applying lubricants like molybdenum disulphide or graphite.