alligator-shears

from The Century Dictionary.

• Shears used for cutting off puddled bars in lengths suitable for piling, and also the crop ends of bars in general. There is a fixed lower jaw, and an upper movable jaw, whose fulcrum is set at the inner end of the cutting portion. Behind the fulcrum the lever is prolonged, and attached to a connecting-rod which receives its oscillatory movement from a crank or eccentric. Also called crocodile- or cropping-shears.