Type F Thread Cutting Floorboard screws feature a thread cutting tip which cuts threads into an existing hole in a trailers metal framing, allowing the user to replace the decking of a trailer without drilling additional holes in framing members. They feature a back phosphate coating and perform best in interior applications such as covered trailers. The star drive eliminates cam-out and provides maximum torque during installation, and the flat head countersinks neatly into the trailer decking for a flush finish.