圈上清式廷大生 Basic Terminology3 Angle of thread Flank Slope→ -0.5p Axis -e!p yoild Crest- Pitch Root- Depth of thread- External thread Internal thread 外螺纹 内螺纹 15 圈上我大峰 Basic Terminology3 ·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,Ψ（螺旋角） >Angle between the screw axis and the rise of the thread ·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. 1615 Basic Terminology3 External thread 外螺纹 Internal thread 内螺纹 16 Basic Terminology3 • 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