These screws consist of an threaded cylindrical shaft that tapers to a point, with a Hex head at the other end. When these are driven into timber, the threads bite into the wood, while the head stops the screw from going all the way through as it provides compression.
Used to fix heavy pieces of timber together and other heavy carpentry applications
Hexagonal head for use with spanner or socket drivers
Coarse single thread
Zinc plated, reducing the corrosion rate in normal atmoshere