THE DEFINITIVE GUIDE TO TYPES OF SCREW HEADS

Hex screw heads are of two types—exterior and inside. External screw heads are hexagonal and protrude within the floor, wanting just like a bolt head. Some hex external screw heads have in-built flanges, while some make do with the hexagon for The top. Also typically often called Robertsons, these screw heads Have got a sq. central issue that ac