Yakozwe mu ifu ya alumina ifite isuku nyinshi, itunganywa hakoreshejwe uburyo bukonje bwo gukanda, gutwika ubushyuhe bwinshi no kurangiza neza, ishobora kugera ku rugero rwo kwihanganira uburebure bwayo kugeza kuri ± 0.001 mm, ubuso bwayo bugashyirwa kuri Ra 0.1, kandi ubushyuhe bwayo bugashyirwa kuri 1600°C.