Axial distance between successive threads. NOTE In a single start thread, pitch is equivalent to lead.
Source: API RP 7G-2, Recommended Practice for Inspection and Classification of Used Drill Stem Elements, First Edition, August 2009. Global Standards
Nominal distance between two adjacent threads roots or crests.
Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global Standards