Bicycle parts chain is power transmission components, in addition to abrasive wear at work under conditions requiring high surface wear resistance, but also because of pedal power and impact arising from road bumps, so they need to have a certain toughness. Material often used in low-carbon steel by carbonitriding or carbon steel is quenched to obtain a lath martensite (ordinary bicycle); quality low carbon or alloy steel after quenching and tempering in the temperature (Senior bike).