• # question_answer It is required to cut screw threads of 2 mm pitch on a lathe. The lead screw has a pitch of 6 mm.If the spindle speed is 60 rpm, then the speed of the lead screw will be: A) 10 rpm             B) 20 rpmC) 120 rmp                       D) 180 rpm

$\frac{Speed\,\,of\,\,lead\,\,screw}{Speed\,\,of\,\,spindle}=\frac{Pitch\,\,of\,\,threads}{pitch\,\,of\,\,lead\,\,screw}$ Speed of lead screw $=\left( \frac{2\times 60}{6} \right)=20\,rmp$