nā ʻāpana wiliwili kūʻai nui IADC217 17.5 iniha (444.5mm)

ʻO ka drill bit kahi mea i hoʻopili ʻia i ka hope o ke kaula drill e moku ana, ʻoki a ʻoki ʻia paha nā ʻano pōhaku i ka wā e wili ai i ka luawai, e like me nā mea i wili ʻia e ʻohi ai i ka wai, ke kinoea, a i ʻole ka ʻaila.
He hakahaka ka bit drill a he mau jet e hiki ai ke kipaku aku i ka wai wili, a i ʻole ka lepo, me ka wikiwiki kiʻekiʻe a me ke kaomi kiʻekiʻe e kōkua ai i ka hoʻomaʻemaʻe ʻana i ka bit a, no ka hoʻokumu ʻana i ka palupalu, kōkua i ka wāwahi ʻana i ka pōhaku.
Tricone drill bits: Aia ka tricone bit ekolu conical rollers me na niho i hanaia me ka mea paakiki, e like me ka tungsten carbide. Haʻi nā niho i ka pōhaku ma ka ʻoki ʻana i ka neʻe ʻana o nā wili ma lalo o ka lua.
PDC drill bits: ʻAʻohe wahi neʻe o ka bit PDC a hana ʻia ma ke ʻoki ʻana i ka ʻili pōhaku me nā niho ʻano diski i hana ʻia me kahi slug o ke daimana synthetic i hoʻopili ʻia i kahi tungsten carbide cylinder.