L = Lead" is the distance traveled when the screw thread turns once. The 2N of a M10X1. 5 2N designates the thread as a two start or is a double thread. Although it will be a bit more difficult to produce, a screw with two starting points is called a two start or double thread.

What does double lead thread mean?

Pitch is the distance from the crest of one thread to the next. ... Because the vast majority of screw threadforms are single-start threadforms, their lead and pitch are the same. Single-start means that there is only one “ridge” wrapped around the cylinder of the screw's body.

What does lead mean in threads?

Lead– The axial distance the nut advances in one revolution of the screw. The lead is equal to the pitch. times the number of starts. Screw Starts – The number of independent threads on the screw shaft; example one, two or four in the. figure below.