Amawasha ayisicaba ensimbi engagqwali ayingxenye ebalulekile emisebenzini eminingi yemishini nesakhiwo. Zisetshenziselwa ukusabalalisa umthwalo we-fastened ene-threaded, njengebhawudi noma i-nut, endaweni engaphezulu, ukuvimbela ukulimala kokubotshwa kwento. Insimbi engagqwali ivamise ukuthandwa ngenxa yokungagqwala nokuqina kwayo, okuyenza ifanelekele ukusetshenziswa lapho ukuchayeka kumswakama noma izindawo ezinokhahlo kuwukukhathazeka.