He mea paahana koʻikoʻi nā ʻāpana ʻoki metala i ka mīkini ʻenehana hou. Inā he mīkini mīkini maʻamau, a i ʻole he mīkini mīkini CNC a me ka mīkini kikowaena kikowaena mīkini, pono e hilinaʻi i ka mea ʻoki e hoʻopau i ka hana ʻoki. I ka ʻoki ʻana, ʻaʻole wale ka ʻāpana ʻoki o ka mea hana i kahi ikaika ʻokiʻoki nui, akā lawe pū nō hoʻi i ka wela kiʻekiʻe i hana ʻia e ka deformation a me ka friction o ka ʻoki kuʻemaka. I mea e hana ai nā lau ma lalo o ia mau kūlana me ka ʻole o ka deformed a i ʻole ka pōʻino koke, a no ka mālama ʻana i kona hiki ke ʻoki ʻia, pono ka paʻakikī o ka wela kiʻekiʻe a me ke kūpaʻa ʻana o nā ʻili, ka ikaika kulou pono, ka paʻakikī o ka hopena a me nā waiwai kemika. Inert, maikai processability (oki, forging a me ka wela lapaau, etc.), 'aʻole maʻalahi e deform, maʻamau ke kiʻekiʻe o ka mea paʻakikī, aʻaʻahu hoʻi ke kū'ē; ke kiʻekiʻe ka ikaika kulou, kiʻekiʻe hoʻi ka paʻakikī o ka hopena. Akā ʻoi aku ka paʻakikī o ka mea, ʻoi aku ka haʻahaʻa o kona ikaika flexural a me ka paʻakikī. ʻO ke kila kiʻekiʻe ka mea i hoʻohana nui ʻia i ka ʻoki ʻoki ma muli o kona ikaika kiʻekiʻe a me ka paʻakikī o ka hopena, a me ka machinability maikaʻi, a ukali ʻia e ka carbide cemented. ʻO ka lua, ʻo ka hana ʻoki ʻana o nā lau e pili ana inā kūpono nā ʻāpana geometric o ka ʻāpana ʻoki a me ke koho ʻana a me ka hoʻolālā ʻana o ka hoʻolālā ʻana.