He apo metala ke apo Piston i hoʻokomo ʻia i loko o ke awāwa piston. ʻElua ʻano apo piston: ke apo compression a me ke apo aila. Hiki ke hoʻohana ʻia ke apo compression e sila i ke kinoea hui ʻia i loko o ke keʻena kuni. Hoʻohana ʻia ke apo aila e ʻeli i ka aila keu mai ka cylinder.
ʻO ke apo piston he ʻano apo hao elastic me ka deformation hoʻonui nui i waho. Hoʻākoakoa ʻia i loko o ke awāwa annular e pili ana i ke ʻano. Hilinaʻi nā apo piston reciprocating a me rotating i ka ʻokoʻa o ke kaomi ma waena o ke kinoea a i ʻole ka wai e hana i kahi sila ma waena o ka pōʻai waho o ke apo a me ka cylinder a me kekahi ʻaoʻao o ke apo a me ke awāwa.
ʻO ke apo piston ka ʻāpana koʻikoʻi o ka mīkini wahie. Hoʻopaʻa ia i ke kinoea wahie me ka cylinder, piston a me ka paia cylinder. ʻElua ʻano ʻenekini diesel a me ka ʻenekini gasoline i hoʻohana pinepine ʻia no nā mīkini kaʻa, ma muli o ka ʻokoʻa o kāna hana wahie, ʻaʻole like ka hoʻohana ʻana i nā apo piston, ʻo ke apo piston mua ma o ka hoʻolei ʻana, akā me ka holomua o ka ʻenehana, ua hānau ʻia ke apo piston mana kiʻekiʻe kila, a me ka hoʻomaikaʻi mau ʻana o ka hana ʻenekini, nā koi kaiapuni, nā ʻano hana lapaʻau ʻili holomua, e like me ka thermal spraying, electroplating, chrome plating, Gas nitriding, physical deposition, surface coating, zinc manganese phosphating treatment, i hoʻomaikaʻi nui ʻia ai ka hana o ke apo piston.
