T/2

T

2 T

4 T

butt joint with single cover plate

butt joint with double cover plate

lap joint with one ring overlapping the other

any one of the above

axial tensile load only

axial compressive load only

combined axial and twisting loads

axial tensile or compressive loads

inaccuracies of tooth spacing

irregularities in tooth profiles

deflections of teeth under load

all of these

The efficiency of a self locking screw can not be more than 50%

The efficiency of Acme (trapezoidal) thread is less than that of a square thread

If the friction angle is less than the helix angle of the screw, then the efficiency will be more than 50%

The efficiency of a self locking screw can not be more than 50% and The efficiency of Acme (trapezoidal) thread is less than that of a square thread