What Is an Electric Shear?

The shear is a tool used to make vertical cuts in different materials. Nowadays you can find different types of shears, such as the manual shear or the electric shear, also called motorised. The latter allow metals of great thickness to be cut, which is why they are widely used in machine shops.

Electric or manual shear?

To cut metals you can use electric shears, but manual ones as well. The difference between these two tools lies in the thickness they can cut; thus, the manual shear is intended for cutting thin materials, from metal plates to wood, plastic and even paper. The electric shear, for its part, is used to cut thick sheets of metal.

The electric shear is manual, since it is the operator who must make the cut in a piece according to the machining needs; however, manual shears may not be electric. It is confusing, but to clear it up we will tell you about the different types of shear that exist today. You should also know that the shear is an electric and manual tool for cutting sheets of ferrous and non-ferrous metals.

These tools work thanks to the shearing principle, which is similar to the one used by scissors, with which you can cut without great effort. Furthermore, electric shears are used in industry so that the cutting of metals is quick and very efficient, since it takes only a few minutes to make the cuts; that said, it is important to point out that the cut made with a shear is not perfect and there may be irregularities on the edges. This type of machine is usually intended for making quick cuts.

Types of shears

By use, shears can be classified as manual and automatic and go by different names:

• Sheep shears
• Pruning shears
• Metal shears, which can make cuts on thin metal surfaces and can be straight-cut, curved to the left and curved to the right.
• Circular shears, which work with an electric motor and are intended for cutting circular parts and rings. They are ideal for cutting aluminium, bronze, brass and mild steel.
• Jaws of life, which can be operated with a manual hydraulic pump or with a motor.
• Industrial shear, which is a large machine tool with a blade that makes vertical cuts. It uses an electric motor to increase the cutting pressure.
• Electric, for cutting sheets or plates of metal of a certain thickness.

Shearing principle

All shears, manual and electric, have the same operating principle, which is called shearing. These tools have two blades that come together pressing hard on the surface until it breaks and separates in two; hence it is said that shears work in a similar way to scissors.

The results when using the shear are more irregular than if the cut is made with a specialised machine tool, but shears are used for their speed and ease of use. The pressure needed to cut the metal can be obtained by applying leverage between the fixed arm of the tool and the movable arm. On manual shears, unlike electric ones, the up-and-down movement that produces the pressure is made by an operator.

How does the electric shear work?

In the electric shear, the force needed to cut is obtained through a mechanical motor or a hydraulic one and, depending on the shear model, the cuts can be made straight or at an angle. However, electric shears, despite having the same operating principle, are characterised by a different structure from that of conventional shears.

These tools are small, mostly portable, and consist of two blades between which the piece of metal to be cut is placed. It is best to clamp the piece to a worktable, using one of the clamping systems and fixings, so that making the cut is easy for the operator. Once the sheet of metal has been inserted between the parts of the electric shear, the tool's motor is started and the shear is slid over the surface of the piece to be cut, as if you were using a pair of scissors to cut fabric, for example. It is important to remember that the edges are irregular and that they may need machining by other methods such as abrasion.

Depending on the model and make of the electric shear, it may require cables and a connection to the mains electricity or be fully portable and charged by the methods specified by the manufacturer. It is advisable for the electric shear to be used by qualified personnel, since one of the main risks of this tool is cuts or amputations; in addition, it is advisable to wear protection such as gloves and earplugs.