Description: Jaw crushers are configured for primary crushing of hardest rock. It crushes without rubbing minimum dust oil lubrication. It has salient features like law wear parts gap adjustment and high capacity overload protection, high operational reliability, long service and life time, easy replacement of wear and spare part. In this process there is no rotary motion in the crushing cycle and all crushing is done by compression of the feed material between two massive jaws. The moving jaws are so balanced that fully 95% of the motor's power is used for crushing while only 5% of the power is needed to move the jaw itself as a results of this high mechanical efficiency is attained. It operates with a single lightweight fly wheel, which is easily started with a normal duty squirrel cage motor. The compression springs provide crushing to the toggle mechanism that eliminate knocks and reduce the resultant wear. The oil resistant flexible diaphragm seals opening in the oil chamber protect the mechanism against dust.