Sq.- Square recess screws Have a very sq.-shaped socket in the center on the screw head. They're also somewhat tapered creating set up quick. The suitable instruments are simple to insert and seldom slip out of position. That is a variation of your counter sunk screw head, but the under https://types-of-house-foundation96162.prublogger.com/28912031/little-known-facts-about-types-of-screw-heads-uk