Countersunk head screw can also be called flat head screw, countersunk head screw, half countersunk head screw, half countersunk head screw.Generally countersunk head screws are cross slot, which is above the national standard specifications, state standards, namely the label for GB/T846-1985. The countersunk head screw in general is metal screw wire pier, formed in the thread rolling, assumes the circular, head of flat head, such as a rake face around the screw on the side, put the screw can lock the nut or other objects.Countersunk head screws have a large diameter at the top and can be rounded or hexagonal in shape to allow tools such as a screwdriver or wrench to turn the screws.The protruding top also prevents the screw from drilling too deep into the material and increases the pressure on the material.Countersunk head screws can usually be removed or reinserted at will without compromising their efficiency, provide more power than nails, and can be reused.Countersunk head screws use the product material, the head can be completely sunk, the screw head will not play an obstructing role.