Sheet metal guillotine shears for straight cuts
A sheet metal guillotine cuts plate along a straight line. The upper blade shears the material against a fixed lower blade. A hold-down clamps the sheet so it cannot shift. What you get is a straight edge with minimal burr and no heat affected zone. No cutting gas, no fume extraction, nothing consumed but the blades. That is why the shear usually runs first in a press brake shop. Everything in this family sits under Sheet Metal Processing Machines.
Guillotine shear or plate shear: one machine, two names
On the shop floor the machine is a guillotine. On the drawing and in the quote it is a plate shear. Catalogs also list swing-beam shears, and that is the KNUTH design. The blade beam swings around a pivot rather than dropping straight down. That holds cutting force down and keeps twist out of the blank. Squaring shear is another word for the same job, not a different process.
Hydraulic, motorized and manual drives
The drive sets the ceiling on plate thickness, cut length and operator effort. KNUTH carries three.
- Hydraulic guillotine shears make their cutting force with hydraulic cylinders. They take the thickest plate and the widest sheets, and they trim finer.
- Motorized guillotine shears run an electromechanical drive with a flywheel. Rugged, low on maintenance, quick between strokes on thin and medium plate.
- Manual lever shears work off operator force. They fit small formats, one-off parts and the maintenance bench.
Heavy plate or steady volume means going hydraulic. Mixed job work is usually happy on a motorized machine.
CNC, NC and the back gauge
An NC machine drives the back gauge to the number you key in. Repeat cuts land on the same dimension. A CNC guillotine shear stores programs and works down a cut list. It also sets the cut angle and the blade gap from the material entry. Shops with many part numbers see the payback first.
Cut angle, hold-down and edge quality
Edge quality comes down to three things. The cut angle decides how far the plate twists while the blade travels. Flatter angle, cleaner edge. Steeper angle, more cutting capacity. The hold-down has to grip the sheet from first contact, and the blade gap has to suit the material. Sheet support and stacking equipment keep large sheets manageable for one operator.
What fabrication shops cut on them
Job shops use a guillotine metal shear to size blanks. Structural steel, tank and vessel work, HVAC duct and truck body shops follow. Material runs from mild steel and stainless to aluminum and copper alloys. Most blanks then head for a press brake, a punch or the weld bay.
Sizing the machine to your shop
Five questions settle it. How thick, and in which material, since stainless needs more force than mild steel. How long a cut, measured on the widest sheet you buy. How many parts per shift, and how clean an edge the next step needs. And what blades and service will cost over the years. Shops that live at the thickness limit should move up a size.
Shear blades and wear parts
Shear blades do the cutting, wear out first and can be reground several times. A dull blade leaves burr and rolls the edge over. Shear blades and wear parts are available through KNUTH.
Safety on the shear
A shear is safe when it is run and maintained the way it was built to be. Depending on the series it comes with a cut line guard, an emergency stop and rear guarding. Foot pedal or two hand controls keep hands clear of the blade line. Light curtains stop the stroke if something enters the danger zone. The machine documentation states what is installed.
When a shear is the wrong tool
Straight cuts are the job of a shear. Holes, cutouts and contours need a different process. Fiber laser cutting machines hold tight tolerances on complex shapes. On heavy plate an industrial plasma cutting machine is the cheaper answer. To form instead of cut, look at sheet metal folding machines and plate rolling machines.
Why KNUTH USA
KNUTH is a machine tool supplier and does not build the machines. We pick the series, check them in Germany and ship them out. Every machine is tested with documentation before it leaves. Machines ship checked against European testing standards, and that documentation is available on request. Our US team works out of Chicago and covers several drive types and machine sizes.
Service, parts and availability
Standard wear parts ship from stock, special parts come directly from the manufacturers of the components. Spare parts supply is guaranteed for ten years on every machine. Service across the Americas runs through our own service organization. Current availability of a guillotine shear is something we confirm on request.
Further Machine Categories at a Glance
Here is an overview of our machine range. Select a category to learn more about individual machines and their technical data.
