This page discusses the pressure requirements for pressing quality bricks with a CEB press.
Pressures on Existing Machines
- 1 kg/cm2 = 14.2 psi (pounds per square inch) - 
- ton - A unit of weight (mass) equal to 2240 pounds (a long ton) or 2000 pounds (a short ton) or 1000 kilograms (a metric ton); A unit of volume ... - [en.wiktionary.org/wiki/ton]
- 1 megapascal = 145.0 pound-force/square inch (PSI) - 
The Liberator 1 featured an operating hydraulic pressure of 2200 psi. We use a 5 inch hydraulic cylinder, or 43,000 pounds of pressure - or about 20 tons.
- This gives a force of 600 psi on the face of the brick.
- The compressive strenght of a brick is another issue. This must be measured by applying pressure to an unconfined brick.
The CEB Prototype 2 will feature a working hydrualic pressure of 2500 psi with a 5 inch cylinder.
- This is 49,000 pounds of force, or 680 psi on the face of the brick
Here are some typical operating pressures found on other machines.
- AECT Impact 2001 machine - 1091 psi force on the brick (72000 lb on 5.5x12 inch brick face) - 
- Auram 3000 - 150 kN (15 metric tons, or 33,000 lb) of pressure on a face of 9.4x9.4 inches, or 373 psi