Shearing is most often used in conjunction with another process such as laser cutting or turret punching. This is the most effective way for our steel fabricators and aluminum fabricators to make long straight cuts up to 12' wide, for up to 0.375" thick mild steel, 0.25" aluminum, and 0.25" stainless steel.
The machine used is called a squaring shear, power shear, or guillotine. The machine may be foot powered (or less commonly hand powered), or mechanically powered. It works by first clamping the material with a ram. A moving blade then comes down across a fixed blade to shear the material. For larger shears the moving blade may be set on an angle or "rocked" in order to shear the material progressively from one side to the other; this angle is referred to as the shear angle. This decreases the amount of force required, but increases the stroke. A 5 degree shear angle decreases the force by about 20%. The amount of energy used is still the same. The moving blade may also be inclined 0.5 to 2.5°, this angle is called the rake angle, to keep the material from becoming wedged between the blades, however it compromises the squareness of the edge.