Swing beam vs guillotine shear: cut quality, capacity and blade life

A swing beam shear suits shops that cut mostly thin to medium sheet, up to about 13 mm mild steel, and want a simple machine with little to adjust. A variable-rake guillotine suits shops that cut thicker plate, narrow strips or mixed materials, where changing rake and blade gap per job keeps parts flat and edges clean.

How the two designs cut

On a swing beam shear the upper blade sits on a beam that pivots, so the blade comes down in a shallow arc. Baykal's HGL line swings on self-aligning roller bearings, and the rake angle (the slope of the upper blade along the cut) is fixed by the geometry: 1.6 degrees on the Baykal HGL 2606. With no guides to adjust, the machine is simple and compact.

On a guillotine shear the blade beam travels straight down on guides, and on modern hydraulic machines the rake is set from the control for each job. Durma's technical data gives about 0.5 to 2.5 degrees on the Durma VS 3013, and Haco and SafanDarley list 0.5 to 3 degrees on the Haco TSX 3012 and the M-Shear. A low rake gives flatter parts but needs more force; a high rake cuts thick plate with less force but distorts narrow strips more.

Swing beam vs guillotine at a glance

Bow, twist and camber

Three defects show up on the strip that drops behind the blades. Twist is a corkscrew along the strip, bow is curl along its length, and camber is a sideways curve seen from above. All three get worse as the strip gets narrower relative to its thickness and as the rake rises, because the blade bends the drop piece while it cuts.

A swing beam's low fixed rake keeps distortion low across its range. RAS, a builder of swing beam shears, states that twist-free parts start at about 10 to 15 times the sheet thickness, so in 3 mm sheet that means strips from roughly 30 to 45 mm wide. A guillotine lets the operator trade force for flatness: drop the rake for narrow strips, raise it for wide cuts in thick plate. SafanDarley's M-Shear corrects the knife-bar stroke automatically when the angle changes and lists torsion-free cutting of small strips. If narrow strips are a large share of your work, cut samples of your own material on both types before you decide.

Cut quality and blade gap

The clearance between upper and lower blade does more to the edge than the shear design. Too tight and the blades wear fast; too loose and the edge rolls over with a heavy burr. The right gap grows with thickness and changes with the material. Haco quotes gaps from 0.05 mm for thin sheet on its TS shears, and the TSX version sets the gap automatically by two hydraulic cylinders according to material thickness. The Ermaksan CNC HVR 3100-10 sets both angle and gap from its ErCut7 control.

Swing beams can do this too. Baykal offers motorised blade gap adjustment as an option on the HGL, and MC Machinery's swing beam line has single-point manual adjustment on the basic model and CNC gap on the upper model. The practical question is whether your operators will change the gap every time the thickness changes. If not, pay for automatic adjustment.

Thickness range

Swing beams are mostly built for sheet. MC Machinery's GH series runs from 4 to 13 mm mild steel and points heavy plate above that to guillotines; Baykal's HGL line goes up to 8 mm. Guillotines cover the full range: Durma's VS series runs from 6 to 25 mm, and Ermaksan's CNC HVR range spans 6 to 40 mm.

Check the stainless figure, not just mild steel. The HGL 2606 is rated 6 mm mild steel and 4 mm stainless, the Durma VS 3013 13 mm and 10 mm, and the Ermaksan CNC HVR 3100-10 10 mm and 6 mm. Cutting stainless or wear plate at the mild steel rating overloads the blades and the frame.

Blade life and blade changes

Most shears in this class use blades with several cutting edges, turned to a fresh edge when one dulls. SafanDarley fits blades with four cutting edges to the M-Shear, and MC Machinery says the four-edged blades on its swing beam shears can be rotated three times before replacement. RAS argues that swing beam blades stay sharp longer because upper and lower blades do not rub as they pass; that is the builder's own claim. In practice, blade life depends mostly on the correct gap, staying within the rated capacity for each material and keeping the blades clean, so the way the gap is set matters more than the name of the design.

Speed, backgauge and floor

Swing beams are quick on sheet: the HGL 2606 runs 24 strokes per minute. Guillotines are slower at full length (7 to 14 on the Haco TSX 3012, 9 to 17 on the Durma VS 3013), but CNC models can shorten the stroke for short cuts: the SafanDarley M-Shear 430-16 runs 8 strokes per minute at full length and 26 at minimum length. The accuracy of your blanks comes mostly from the backgauge; Ermaksan quotes 0.1 mm on its 1,000 mm motorised gauge.

Guillotines built for plate are heavy. The Durma VS 3013 weighs about 12,860 kg and the Haco TSX 3012 about 8,500 kg, against about 4,700 kg for the lighter-duty HGL 2606. Check your slab before ordering with our guide to preparing your floor for machine installation. Both types need hold-downs and guarding at the blade and behind the machine; in British Columbia, WorkSafeBC's Part 12 guidelines refer to CSA Z142 and ANSI B11.4 for shear safeguarding, and other provinces set their own rules.

Which shear for which shop

• HVAC, ductwork and light fabrication in sheet up to about 6 mm: a swing beam gives fast, clean cuts with little to set.
• General fabrication up to 13 mm with regular narrow strips: a CNC variable-rake guillotine with automatic blade gap.
• Heavy plate for trailers and agricultural equipment: a guillotine in the 13 to 25 mm class or above.
• Tight budget and mostly one thickness: a swing beam, set up once and left alone, is hard to beat.

All current models are listed on the shears page.