A kusurwa yanke bawul ne cylindrical bawul, hatimi ne a kan wani sama ko cone, bawul a kan tsakiyar layin ruwa don daidai motsi. Ƙasar misali yanke bawul ne kawai dace da cikakken bude da kuma cikakken kashe, gabaɗaya ba a yi amfani da shi don daidaita kwararar, an yarda da daidaitawa da rage kwararar lokacin da aka tsara