Page 13 - Threading_Handbook

Starts
According to the number of starts, the threads are divided into single-start and multi-start
threads. A single-start thread has one continuous thread running along the body of the
screw. A multi-start thread consists of two or more intertwined threads running parallel
to one another. The lead distance of a double-start thread is twice that of the single-start INTRODUCTION
thread and a triple-start thread has triple that of the single-start thread. For example, if the
end of the workpiece part is divided into two or three equal parts, and the threads start from
each of these points, then this indicates double or triple thread starts.

Single-Start Double-Start Triple-Start

Lead Lead Lead
Pitch Pitch Pitch

Lead=Pitch Lead=2xPitch Lead=3xPitch

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