Kev siv tsheb siv hlau rau crankshafts (4140 tshav kub {{1} {{{}}}}} Cov khoom siv ncua kev ncua (Q345). Siab - muaj zog qis {}}}}}}}}}}}}}}}}}} pa tawm hauv chassis seem, txhim kho roj efficiency. Stainless Hlau Rounds (304, 316) yog siv rau kev tso pa tawm (corrosion tsis kam) thiab roj kab tsis kam) thiab roj kab. Txias-drawn rounds nrog nruj rau kev ua siab ntev yog nyiam rau qhov chaw ua kom zoo li bearings, ua haujlwm du thiab ruaj khov nyob rau hauv cov nra hnyav.