A Distinctive type of bolt that's set into concrete, with screw threads protruding earlier mentioned the concrete floor to simply accept a nut. Pin screws are Just about the most frequent tamper resistant screw, they've got very same layout just like a cross form in Philips screw getting extra layer https://caidenbrixj.blog5star.com/29752890/the-ultimate-guide-to-types-of-screw-heads-with-pictures