Whenyoudriveascrewintowood,it’seasierifaholeisalreadythere.That’swhereadrillhelps.Andguesswhat?Adrillbitisa screw.

Amotorspinsthedrill.Thetipofthedrilldigsintothewood.Inafewseconds,youhaveasmall hole.

Somelargerdrillsmakelargerholes.Theydigholesinthegroundtomakewells.Theyalsomakeholesforfencepostsandtelephone poles.

Mostscrewsspinroundandround.Butsomescrewsdon’tmoveatall.Thinkofaspiralstaircase.Aspiralstaircaseisshapedlikea screw.