Geometrical data exchange files in the <STEP> format normally have an *.stp or *.step extension. <STEP> format allows the transfer of a multitude of different types of geometrical objects. This is why one can achieve data transfer between different systems with virtually no distortion. The <STEP> format is widely used, especially in areas where high data transmission accuracy is required due to very complex three-dimensional geometrical models.
There is build-in module for direct import STEP at SprutCAM.