Flat Head Socket Cap Screws - Metric Sizes
A2 Stainless Steel Countersunk Flat Head Internal Hex Drive Screws
A countersunk flat socket cap screw head driven with a socket Allen hex key wrench, metric socket cap screws A2 stainless steel fasteners are flat heads. A flat socket cap screw, also known as a countersunk socket cap screw, countersunk flat socket screw or Allen flat head socket bolt, is a type of cap screw with a flat head and hexagonal (Allen) drive hole. The term flat socket head cap screw typically refers to a type of threaded fastener whose head diameter is nominally 2 times or more that of the screw shank diameter.