There are 2 types of hex screws: An Allen screw incorporates a hexagonal indent in the head, necessitating an Allen wrench, and one other sort has no indent during the hexagonal head and has to be used or removed by using a socket wrench. The duration of those screws varies, https://woodscrews46058.jts-blog.com/28122292/indicators-on-wood-screws-you-should-know