When breaking oversize material the hydraulic breaker is expected to break the material down quickly into multiple pieces. This is optimum production. If the operator has to re-position the breaker towards the edge of the rock and gradually downsize the material, production rate slows down.
To assess which breaker will effectively handle this application, the size and hardness of the material must be known. For example, if a 4 cu. yard piece of hard rock (20,000 psi or greater) needs to be broken in half you require a 7,500-ft. lb. or larger breaker. If a 2 cu.yd. piece of limestone (20,000 psi or less) needs to be broken in half you require a 3,000 - 5,000-ft. lb. hydraulic rock breaker.
Up to 1100-ft.lb. class (1627 Joules), are typically used in concrete and other light duty work.
1200 - 4000-ft.lb. class (1627 - 5423 Joules) are used in both concrete and rock applications with limitations on the size and amount of material to be broken.
Over 4000 ft. Lb. class (5423 Joules), are typically used in hard rock, high production applications.