A shearing machine cuts sheet metal and steel plates in a straight line using an upper blade that moves down against a fixed lower blade. It produces clean, square cuts without heat, sparks or material loss. That makes it the standard machine for cutting sheets and plates to size in fabrication, sheet metal and steel processing workshops.

In a guillotine shearing machine the upper blade moves straight down in a vertical line, and the rake angle can usually be adjusted. This gives higher cutting precision, less plate distortion and longer blade life, and it suits thicker plates and precise work. In a swing beam shearing machine the upper blade holder swings in an arc around a pivot. It is simpler and more economical, and it suits general sheet and plate cutting where the highest precision isn’t critical.

A hydraulic shearing machine uses hydraulic cylinders to drive the upper blade instead of a mechanical flywheel and crank. The hydraulic system provides a large, adjustable cutting force and a smooth stroke, with built-in overload protection. Both guillotine and swing beam shears are commonly hydraulic, because hydraulics give reliable performance on thick plates with lower noise and less maintenance than mechanical shears.

A CNC shearing machine uses a numerical control system to position the backgauge automatically and control the cutting cycle. The operator enters cut lengths and quantities, and the machine repeats them accurately without manual measuring. This speeds up batch cutting, improves accuracy and reduces errors and material wastage.

Yash Machine Tools, based in Ahmedabad, supplies four types of shearing machines:

• QC11Y Series hydraulic guillotine shearing machines
• CNC guillotine shearing machines
• Hydraulic swing beam shearing machines
• CNC swing beam shearing machines

The range covers plate thicknesses from about 4 mm to 25 mm, with cutting lengths up to several metres, to suit workshops from light fabrication to heavy plate processing.

The rake angle, or shear angle, is the angle between the upper and lower blades. A smaller rake angle reduces bending and twisting of the cut strip, which is better for thin sheets and precise cuts. A larger rake angle reduces the force needed to cut thicker plates. On a hydraulic guillotine shear the rake angle can be adjusted, so the operator can balance cutting force and cut quality for each thickness.

Start with the maximum plate thickness and length you need to cut, and the type of material, since stainless steel needs more capacity than mild steel. For thicker plates and precise cuts with minimal distortion, choose a hydraulic guillotine shearing machine. For general sheet and medium plate cutting on a budget, a swing beam shearing machine is a good choice. If you cut many parts to repeated sizes, add a CNC backgauge to improve speed and accuracy.

The backgauge is the adjustable stop behind the blades that sets the length of each cut. The operator moves it to the required size and pushes the sheet against it before cutting, so every piece comes out the same length. Backgauges can be manual, motorised with a digital display, or CNC controlled. A swing-away backgauge also lets the machine cut sheets longer than the backgauge travel.

Keep the blade gap set correctly for the thickness being cut, because a wrong gap causes burrs, rough edges and faster wear. Never cut material thicker or harder than the machine’s rated capacity. Keep the blades clean and check them regularly for chipping. Most shear blades have four cutting edges, so they can be rotated to a fresh edge before they need regrinding, which extends blade life considerably.

Shearing machines are used in sheet metal fabrication, steel service centres, HVAC ducting, electrical panel and enclosure making, automobile and body building, agricultural equipment, structural steel fabrication, tank and pressure vessel making, and general engineering. Any business that cuts metal sheets or plates to size relies on a shearing machine.