Manufacture of machinery and metal must be used . Before forging Arab architectural metal usually relatively tight , can not withstand large forces , should have forged Arabia to make them become permanent tightly adapted for the manufacture of spare parts bearing large ! The earliest method was used forging dies hammer . Uncle blacksmith pliers clamped piece of metal was heated to iron hammer and anvil and hammer pounding each step of forging hammer in animals . This method has both exhausting slow , but heavy forging read few kilograms details . Later, people invented the steam hammer and pneumatic hammer forged probable toxic components weighing up to several tons . But the greater detail machine is no way to be forged . Get a 250 ton heavy iron bars as if , if 7 meters long , then its diameter is 2 , 7 meters , if the separation must be used to transport large 50 new passenger cars before. The large forgings so, do not talk to the doctor about the blacksmith hammer does not hold well , even hammer pneumatic hammer and not coping well . Hence, the user appears to forging hydraulic press . Hydraulic much like a college athlete , hand it to the steel ingots weighing several hundred tons situation turns into arbitrary shapes . Why hydraulic presses have read so much pressure ? That reason is because hydraulic presses are manufactured in accordance with the laws of fluid pressure transmitters . In the 17th century , the French scientist Pascal discovered experimentally that pressure ( ie the pressure that each ministry area suffer ) of the external forces acting on the fluid sealed transmissions as plucking each other in the liquid . In general, hydraulic presses are two different cylinder capacity , cylinder pipe between two interconnected , and each cylinder has a piston fit . For such a pressure effect as the piston is 10 KGL small area of 2 cm 2 , the liquid will probable bring pressure on KGL 5 1 cm 2 transmission to 400 cm 2 area of the large piston , to make per cm2 for the area of the large piston is subjected to a pressure of 5 KGL . Such large reciprocating community has all the pressure KGL 2000 . Suppose we exaggerate the large piston area to 1,000 times smaller piston , the piston pressure generated on nearly 1000 times greater pressures will impact on the small piston , in 5000 KGL . Hydraulic presses manufactured by the principles read on . Hydraulic presses are of various kinds , hydraulic forging machine is only in such a large industry . This hydraulic forging probability divided into two types : hydraulic forging machine without obligations or liability and machine forging ties . Hydraulic Forging no obligations or liability tied to work like forging hammer , forging presses probability it was red-hot billet few dozen , a few hundred , a few thousand depending on the status of the form attention . Forging machine is not the same . Put the roasted red steel on steel mold presses used one or more times will be the most detailed picture status determination . Weight is not much of details , usually from a few dozen to a few hundred kHz , but there are some details only once and hammered try to use the huge new pressures . In terms of the theory is that there is probability of making e ] reachable hydraulic presses immense pressure , but their structures are not simple will , so now in the world of hydraulic forging machine no obligations or liability and is not tied biggest crossed 15,000 tons , forging machines and racquet over 100000 tons . China to design and manufacture hydraulic forging machine without obligations or liability bondage 12000 tonnes , probable heavy steel forgings read up to 250 tons . Now all the world community to have only a few dozen hydraulic presses over 10000 tons , and only a few countries that have been identified fabrication .