The winged self-tapping screws from adunox for wood-to-metal connections.

The "wings" are used to mill a hole in the wood with a larger diameter than that of the screw thread. (... so that the screw head can tighten the wood firmly to the metal).

The drill bit is used to pre-drill the correct diameter for the thread into the metal.

The "wings" break off when they enter the metal. Then the internal thread is cut from the screw thread (external thread) and the fastening is completed.

You can find more information about these screws on our category page "Woodwork screws zinc plated"