ʻO ke apo ʻo Quenching + tempering. ʻO kaapo-apoHoʻomaʻamaʻa ʻia i kahi mahana kūpono (quenching temperature 850 ℃, tempering temperature 590 ℃) a mālama ʻia no kekahi manawa, a laila hoʻokomo ʻia i loko o ke kikowaena e hoʻomaha koke.

50 c8 apo -Ke kinai ana.