Hauv cov kab ntim khoom niaj hnub no-txawm hais tias qhwv cov khoom noj khoom haus lossis cov khoom siv tshuaj sib khi-kev ntseeg siab yog tsis sib tham. Cov tshuab tom qab cov dej num no khiav ceev, kub, thiab nyob rau hauv qhov kev vibration tas li. Txhawm rau ua kom txhua yam ua haujlwm zoo, cov kws ua haujlwm vam khom lub qhov (socket head bolts) rau lawv qhov sib xyaw ua ke ntawm lub zog, qhov tseeb, thiab qhov chaw ua haujlwm.