ʻO ka Ball Screw kahi wili hānai kiʻekiʻe me ka pōpō e hana ana i kahi neʻe ʻōwili ma waena o ke axis screw a me ka nut. Ke hoʻohālikelike ʻia me ka wili hoʻoheheʻe maʻamau, loaʻa kēia huahana i ka torque o hoʻokahi hapakolu a i ʻole ka liʻiliʻi, kūpono loa ia no ka mālama ʻana i ka mana kaʻa kaʻa.