wili heleuma kila kuhiliʻole: He ʻano like ia me ke koʻokoʻo cylindrical. Hoʻopili ʻia kekahi ʻaoʻao o ka wili me ka nati, a ʻo kekahi ʻaoʻao he poloka wili conical i kahakaha ʻia me nā ʻano anti-slip. Hanaʻia me ke kila kalapona, ke kila kila a me nā mea'ē aʻe, he haʻahaʻa ke kumu kūʻai, hilinaʻi i ka heleuma, a heʻokoʻa ke kūpaʻa corrosion a me nā mea mechanical. Hoʻohana nui ʻia ia i ke kūkulu ʻana, Bridges, ʻoihana a me ka uila a me nā māla ʻē aʻe.