5. Glossary

Apex; apex

Zone separating the sheaths of the two screws when they are not interpenetrated.

Self-cleaning; self-wiping

Characteristic of a geometry where the surface of one screw perfectly matches the surface of the neighboring screw.

Nombre de filets ; number of flights

This is the number of screw threads starting from a section perpendicular to the axis and winding around the screw. In practice, single-, double- and triple-thread screws are available.