ʻO ka nānā ʻana ma muahoʻonā welaʻo ia ke kaʻina nānā mua o ka huahana i hoʻopau ʻia e like me ka mea i ʻōlelo ʻia ma kake kalaiwa anaʻāpana kiʻi a me ka hana kāleka no ka maikaʻi o ka ʻili a me nā ana o waho ma hope o ka pau ʻana o ke kaʻina hana forging. Pono ka nānā pono ʻana i nā ʻano penei:

① Pono ka helehelena me ka ʻole o nā māwae, nā ʻōpala, nā unahi oxide a me nā puʻupuʻu ma ka ʻili o ka mālama wela.

②Kakiʻi kiʻi o ka die forginge hōʻike i nā ana nui, nā ʻāpana ʻano kūikawā, nā ʻāpana o ke keʻa, ke ʻano a me ke kūlana o nā lua.
③Ka nui a me ka pololei o ka makenā kalaiwano ka mālama ʻana i ka wela e hōʻike i ka ʻae mīkini, ka ʻili o ka ʻili, ka pololei o ka dimensional, ka pololei o ke kūlana a me ka pololei o ke ʻano, etc.

④Nānā nā mea nānā i ka nui o ka underpressure e pili ana i ka 10%-20% o ka helu batch o nā mea hoʻoheheʻe make. Ke hui ka pūʻulu forgings i nā kaha kiʻi, hiki iā lākou ke komo i ke kaʻina nānā. Pono e hoʻokaʻawale ʻia nā forging i hala i ka nānā ʻana ma mua o ke kinai ʻana.

⑤E nānā i ka pahu huahana i hoʻopau ʻia ma mua o ke kinai ʻana, e hoʻokomo i 1-2 mau ʻāpana forgings no ka laʻana (ʻaʻole hiki ke hoʻohana ʻia nā ʻōpala i pelu ʻia a nahā no ka laʻana), a e kaha i ka "sampling" ma kamake forgings. Hōʻike i ka ʻokoʻa.

⑥ Ma hope o ka nānā ʻana, pono e hoʻopiha pololei ʻia ka helu o nā huahana i hoʻopau ʻia, nā ʻōpala hiki ke hoʻoponopono ʻia, nā ʻōpala hope a me nā code defect ma ke kāleka e pili pū ana a pūlima ʻia e ka mea nānā.