It is the most used steel in the world. The countersunk screw head is designed in a way to be sunk into the panel when driven into it. There are 316 Allen Key Countersunk Screw types which are made up of a more corrosion resistant material. The csk screws can also be self tapping screws. There are different types and sizes such as the M6 CSK Allen Cap Screw made for different applications. The allen cap can be tightened and loosened with allen keys. These are useful to install the screws into limited and narrow space. The CSK Allen Head Screw is used in wooden, metallic, marine, general corrosive and many other domestic application types. As a leading supplier and manufacturing of the different allencsk screws.