Press forging is the process of gradually changing a steel billet’s shape by compressing the steel between two large dies that are either hydraulically or mechanically manipulated. However, it’s not just about applying pressure. 

The raw material is heated to a temperature that surpasses its recrystallization temperature (400 degrees Celsius to 700 degrees Celsius, or 752 degrees Fahrenheit to 1,292 degrees Fahrenheit). Once that happens, the crystal lattice structure of the steel is broken down, making the steel more ductile.

Due to the heating process, the steel becomes “softer” or more malleable, so its shape can be changed more easily by the pressure applied by the two dies. 

Our team at Trenton Forging controls the steel temperature during the forging process and the cooling rate to meet a customer’s specific tensile strength and hardness requirements.

What Presses Are Used in This Method?

Three types of presses can be used in the forging process: mechanical, hydraulic, and screw.

Mechanical presses convert the rotational power of a motorized flywheel into compressive force by way of either a knuckle joint, eccentric, or other mechanism to apply pressure onto the steel billet. 

A hydraulic press uses fluid pressure to create force. In a hydraulic press, the pump fills up the cylinder immediately below the piston, which causes the pressure on the piston to increase. Then, the fluid is released through another channel above the piston. It’s this constant build-up and release of pressure through the top and bottom of the piston that makes the hydraulic press move up and down. Hydraulic presses are sometimes used for open die forging. 

A screw press uses both hydraulic and mechanical motors. The rotational energy in the flywheel and screw is converted into the downward force of the ram. The screw continuously produces energy through rotation as the ram pushes down. After one full stroke, the flywheel and screw reset to their original position, and the process starts again.

At Trenton Forging, we use mechanical presses because they tend to be faster than hydraulic presses and screw presses.

Benefits of Press Forging

The immediate benefit of press forging is that it produces a component with fantastic mechanical properties, such as better fatigue resistance and improved tensile strength. Additionally, press forging requires less draft than hammers, typically produces less scrap, and can be more economical for high-volume jobs.

Have Questions? Contact Trenton Forging Today

Founded in 1967, Trenton Forging is an industry-leading manufacturer specializing in hammer and press impression die forging. We can produce asymmetrical and symmetrical forgings from steel, stainless steel, steel alloys, and micro-alloys. Please contact us today if you have questions about press forging or want to learn more about our capabilities.