Cross recessed countersunk head drilling screws with tapping screws thread  

These Flat Head screws have a point “like a drill bit”, these screws create their own hole, and their own thread in one action.
This is probably where the confusion with self-tappers comes in – both kinds of screws are technically self-tapping as far as 
the function of their threads are concerned, but the massive difference is in the function of their points.
* High Quality Steel with Superior Rust Resistant Ensure, More Solid and not Easy to Break;
* It is wood drill tail screw, mainly used in steel structure caigang watt fixed can also be used for fixing the simple
construction of the sheet material;
* How to use? Self-Drilling Screws, eliminate the need for a pre-drilled hole. The length of the drill point determines the
material thickness which the screw can reliably penetrate. When selecting a self-drilling screw design, it is important to
consider the material thickness and type of materials to be joined. These stainless are great to use in environments that are damp
* Package: Poly Bags, Plastic Boxes, Cartons, or Customized.
Features
*Countersunk Self-Drilling Screws - Plain Plated
*Stainless steel 
*Countersunk head
*Phillips cross head drive
*DIN 7504P H