• # question_answer   A single short thread of pitch 2 mm is to be produced on a lathe having a lead screw with a double start thread of pitch 4 mm. The ratio of speeds between the spindle and lead screw for this operation is: A) 1 : 2                             B) 2 : 1C) 1 : 4                             D) 4 : 1

$\frac{Spindle\,\,of\,\,fset}{Lead\,\,screw\,\,speed}$ $\frac{pitch\,\,of\,\,threads\,\,to\,\,be\,\,produceed}{Number\,\,of\,\,starts\times Pitch\,\,of\,\,threads\,\,of\,lead\,\,screw}$$=\frac{2}{2\times 4}=\frac{1}{4}\,\,or\,\,1:4$