Lead is the axial advance of a helix or screw during one complete turn (360°)[1] The lead for a screw thread is the axial travel for a single revolution.[2]
Definition of lead per ANSI/AGMA 1012-G05
Definition of lead angle per ANSI/AGMA 1012-G05
Depiction of the lead angle of a screw thread. dm is the mean diameter of the screw thread.
Pitch is defined as the axial distance between adjacent threads on a helix or screw. In most screws, called "single start" screws, which have a single helical thread along their length, the lead and pitch are equal. They only differ in "multiple start" screws, which have several intertwined threads. In these screws, the lead is equal to the pitch multiplied by the number of "starts".
Lead angle is the angle between the helix and a plane of rotation. It is the complement of the helix angle, and is used for convenience in worms and hobs. It is understood to be at the standard pitch diameter unless otherwise specified.
The lead angle can be expressed as:
where
l is lead of the helix
dm is mean diameter of the helix
In American literature λ is used to notate the Lead Angle.[3] In European literature, Υ (Greek letter gamma) may be used.
lead, engineering, lead, axial, advance, helix, screw, during, complete, turn, lead, screw, thread, axial, travel, single, revolution, definition, lead, ansi, agma, 1012, definition, lead, angle, ansi, agma, 1012, depiction, lead, angle, screw, thread, mean, d. Lead is the axial advance of a helix or screw during one complete turn 360 1 The lead for a screw thread is the axial travel for a single revolution 2 Definition of lead per ANSI AGMA 1012 G05 Definition of lead angle per ANSI AGMA 1012 G05 Depiction of the lead angle of a screw thread dm is the mean diameter of the screw thread Pitch is defined as the axial distance between adjacent threads on a helix or screw In most screws called single start screws which have a single helical thread along their length the lead and pitch are equal They only differ in multiple start screws which have several intertwined threads In these screws the lead is equal to the pitch multiplied by the number of starts Lead angle is the angle between the helix and a plane of rotation It is the complement of the helix angle and is used for convenience in worms and hobs It is understood to be at the standard pitch diameter unless otherwise specified The lead angle can be expressed as Lead angle arctan l p d m displaystyle mbox Lead angle arctan left frac l pi d m right where l is lead of the helix dm is mean diameter of the helixIn American literature l is used to notate the Lead Angle 3 In European literature Y Greek letter gamma may be used See also EditList of gear nomenclature LeadscrewNotes Edit Gear Nomenclature Definition of Terms with Symbols American Gear Manufacturers Association p 72 ISBN 1 55589 846 7 OCLC 65562739 ANSI AGMA 1012 G05 Thread form terms Retrieved 2008 12 22 Juvinall amp Marshek Fundamentals of machine component design John Wiley amp Sons Asia 2006 Page 391 External links EditCalculation of Thread Lead Angle online calculator on Mitsubishi Materials site Mitsubishi Materials Retrieved from https en wikipedia org w index php title Lead engineering amp oldid 1138551654, wikipedia, wiki, book, books, library,
