圈上泽文通大华 Basic Terminology 口External Threads(外螺纹) >the threads on a screw ▣Internal Threads(内螺纹) >the threads on a nut 口Engagement Length,Le(旋合长度) >length over which the nut and the screw are engaged. 圈上大学Multiple Screw Threads(多线螺纹 Screws can be multiple-threaded by having two or more threads cut beside each other ▣Double-threaded screw(双线螺纹) >lead is equal to twice the pitch,/=2p ▣Triple-threaded screw(三线螺纹) >lead is equal to 3 times the pitch,/=3p Advantage of multiple threads:They have >Smaller thread height >Increased lead for fast advancement of nut. Standardized products all have single thread 1010  External Threads（外螺纹）  the threads on a screw  Internal Threads（内螺纹）  the threads on a nut  Engagement Length, Le（旋合长度）  length over which the nut and the screw are engaged. Basic Terminology Multiple Screw Threads（多线螺纹）  Screws can be multiple-threaded by having two or more threads cut beside each other  Double-threaded screw（双线螺纹）  lead is equal to twice the pitch，l=2p  Triple-threaded screw （三线螺纹）  lead is equal to 3 times the pitch, l=3p  Advantage of multiple threads: They have  Smaller thread height  Increased lead for fast advancement of nut.  Standardized products all have single thread