What is a hydraulic sheet metal shear used for?

The hydraulic sheet metal shear is a machine tool used to cut metal plates (sheets) of different thicknesses or gauges. This machine works through a mechanism that applies pressure by the effect of a liquid or gas, that is, it cuts by pressure.

What types of hydraulic sheet metal shear are there?

As you well know, sheet metal is machined on press brakes. Press brakes are used to shape or form sheets of different dimensions and thicknesses. When it comes to stainless steel, unless the sheets are made to measure, they usually come in a standard size: 3000 x 1500, 3000 x 1250, etc. What if you want to cut the metal plate and give it different dimensions? You can use different cutting tools, one of them being the hydraulic shear for sheet metal.

In the metalworking industry there are two different types of hydraulic shear:

• Guillotine. The guillotine shear is used to cut metal plates into sheets (blanks) and has a double action. This machine is characterised by the fact that it is possible to adjust the pressure exerted on the metal according to cutting needs. It is a very precise machine, with high cutting speed, and is easy to operate.
• Swing-beam. The hydraulic swing-beam shear, also called the hydraulic plate shear, has spacers and screens on which the cutting speed can be seen. The gauge and the number of cuts it makes can also be adjusted.

What is the function of the hydraulic sheet metal shear?

Hydraulic sheet metal shears are used for cutting metals, but also other materials such as plastics and wood. It is very important to know that for a hydraulic shear to work properly, the plate of material must have a specific thickness. The greater the thickness or gauge, the more pressure the operator will need to apply to the machine. Although it is a very easy machine to use, the operator must be experienced in cutting with a hydraulic sheet metal shear, otherwise the surface of the material being worked could be damaged.

As we mentioned earlier, sheets, unless they are made to measure, come in standard sizes. For example, if you have a machining workshop and buy sheets from a supplier, they will sell them to you in the sizes in which sheets are made in a specialised workshop. These standard sizes vary only in thickness. So we find sheets of 3000 x 1500 x 5; 5 being the dimension that refers to the thickness of the plate. Following this example, suppose that you only need to use part of that sheet and that the sheet you need is 3000 x 500. Unless you order the sheet with the specific dimensions and for series production (otherwise it will not be economically viable), the supplier will provide you with a 3000 x 1500 x 5 sheet. How do you obtain the metal plate you need for a specific job?

To do this you will need to cut the part using a machine tool such as the hydraulic shear. Can you use a cut-off saw or bandsaw? Laser cutting? The bandsaw can be used, but its use requires an expert operator, as the saw is a good machine but carries certain risks. Laser cutting is an excellent choice, but investing in a specialised machine can be quite expensive if the workshop does not need to use this machine often.

That is why the hydraulic shear for sheet metal is the best option. It is a very versatile machine, easy to operate and considerably cheaper than one that cuts by laser, for example.

Tips for using the hydraulic sheet metal shear

Like all machine tools, the hydraulic shear also needs specific maintenance and care. This will extend the service life of the machine, but also ensures that the work is accurate. If you want the machine to work properly, the first thing you will need to do is check the machine's oil levels; being hydraulic, the shear needs a working fluid, in this case oil.

In addition, you should also check that the safety spacers are in place and do not move for any reason; it is advisable to respect the cutting capacity of the shear: be careful about trying to cut sheets with thicknesses of 20 millimetres, for example. For this you will need to check the capacity of the shear stated by the manufacturer.

A hydraulic sheet metal shear must not be operated by two people, nor should the parts to be cut be held. In addition, lubrication of the cutting blade is very important, as is changing the oil frequently.

How does the machine work?

The most modern hydraulic sheet metal shear, and the most popular today, works in a very simple way. The cutting process is usually almost completely automated. All you need to do is place the sheet on the table of the machine tool, horizontally. This table is fitted with guides and bearings that make machining easier.

If the machine has a control panel, you only need to enter the cutting dimensions you want to make and the type of material being worked. The machine will make the cut by itself. You can even save the cutting dimensions as frequents or favourites; this way you will only have to browse to the cutting program most used in the workshop, without needing to configure the device every time it is used.