A socket cap screw, often known as a socket head capscrew, socket screw, or Allen bolt, can be a type of cap screw with a cylindrical head and hexagonal generate hole. The term socket head capscrew ordinarily refers to the type of threaded fastener whose head diameter is nominally one.5 https://types-of-south-florida-ro25814.smblogsites.com/29366705/facts-about-types-of-screw-heads-uk-revealed