Thread Terminology Flashcards
The longitudinal centerline that passes through the screw thread cylinder.
axis
The angular relief at the thread: allows easier engagement with the mating part.
chamfer
The peak or top surface of a screw thread.
crest
The distance between the crest and root of a thread usually measured normal to axis.
depth
A tool used to form exterior threads.
dye
The screw thread on the outside of a cylindrical or conical surface.
external thread
The screw on the inside of a cylindrical or conical surface.
internal thread
The distance a screw will travel when turned 360 degrees, or one revolution.
lead
The largest diameter on a internal or external thread.
major diameter
The smallest diameter on a internal or external thread.
minor diameter
The distance between corresponding parts on adjacent thread forms, measured parallel to the axis.
pitch
The diameter of an imaginary cylinder that is located equidistant between major and minor diameters.
pitch diameter
The bottom screw thread cut into a cylinder.
root
A continuous and projecting helical ridge on a cylinder or conical surface.
screw thread
The screw thread that connects the crest and the root.
side
