The angle of inclination of the generatrix to the normal section is greater than the pitch angle of the fillet helix. The surface is not developable. The normal section shows a curved circular involute. The helix of the frame is a double line of the surface.

A screw surface is described by a curve that performs a screw movement around an axis. If a straight line is chosen as this curve, a distinction is made between closed and open screw surfaces, depending on whether the straight line used intersects the screw axis or not.

Three main types of open screw surfaces can be distinguished, which are represented by models 1 to 3 of this series. Of the closed screw surfaces particularly used in technology, models 4 and 5 show two main types. For open screw surfaces, the "fillet screw line" is the location described by the intersection of the straight line and its shortest distance with the axis during screwing.

The generators of the surface are indicated by yellow threads, and the double lines by red threads. One turn of the screw surface is shown, the latter bounded by a coaxial cylinder.