friction angle is less than helix angle

friction angle is more than helix angle

friction angle is equal to helix angle

efficiency of screw is 100%

brittle materials

ductile materials

plastic materials

non-ferrous materials

regain its original shape after deformation when the external forces are removed

draw into wires by the application of a tensile force

resist fracture due to high impact loads

retain deformation produced under load permanently

0.45

0.65

0.85

1

uniform velocity

simple harmonic motion

uniform accleration and retardation

cycloidal motion