图上活文通大华 Basic Terminology Angle of thread -Flank Slope→- -0.5p Axis eip youd Crest- -Pitch Root- Depth of thread- 圈上泽支大学 Basic Terminology ·Lead,/(导程) >Distance the nut moves parallel to the screw axis when the nut is given one turn ·Lead Angle,,(导程角、升角) >Angle between the perpendicular of the screw axis and the rise of the thread ·Helix Angle,.w(螺旋角) >Angle between the screw axis and the rise of the thread F/2 ·Thread Angle,2a(牙型角2a、牙 侧角a) >a:Angle between the perpendicular to the screw axis and the crest of the thread. 99 Basic Terminology • Lead, l（导程） Distance the nut moves parallel to the screw axis when the nut is given one turn • Lead Angle, （导程角、升角） Angle between the perpendicular of the screw axis and the rise of the thread • Helix Angle,  （螺旋角） Angle between the screw axis and the rise of the thread • Thread Angle, 2 （牙型角2  、牙 侧角 ）  ：Angle between the perpendicular to the screw axis and the crest of the thread . Basic Terminology