Izikrufu ezikhethekileyo ezimise okwezikrufu zingaphinda zibizwe ngokuba ziibholiti ezibunjwe ngokukhethekileyo, oku kuthetha ukuba izikrufu ezingenayo imigangatho yelizwe zibizwa ngokuba zizikrufu ezikhethekileyo.Ngokuqhelekileyo zisetyenziselwa iziganeko ezikhethekileyo kunye neenjongo.Umahluko kwi-screws eqhelekileyo ulele ekubeni kukho imigangatho yelizwe.
Xa kuthelekiswa nemigangatho ye-screw fasteners, izikrufu ezingaqhelekanga zibonisa iimpawu eziphezulu kwiinkalo ezininzi.Xa sijongene nemfuno enkulu yemarike, kufuneka sihambisane nophuhliso lwamaxesha kunye nesantya sophuhliso loluntu.Izikrufu ezingaqhelekanga ngokuqinisekileyo sesona sixhobo silungileyo.