both sides. They are generally very large, similar in size to a head saw. Construction Feed mechanisms Gravity feed saws fall under their own weight. Most such saws have a method to allow the cutting force to be adjusted, such as a movable counterbalancing weight, a coil spring with a screw-thread adjustment, or a hydraulic or pneumatic damper (speed control valve). The latter does not force the blade downwards, but rather simply limits the speed at which the saw can fall, preventing excessive feed on thin or soft parts. This is analogous to door closer hardware whose damping action keeps the door from slamming. Gravity feed designs are common in small saws. Hydraulic feed saws use a positive pressure hydraulic piston to advance the saw through the work at variable pressure and rate. Common in production saws. Screw feed saws employ a leadscrew to move the saw. Fall mechanisms Pivot saws hinge in an arc as they advance through the work. Single column saws have a large diameter column that the entire saw rides up and down on, very similar to a drill press. Dual column saws have a pair of large columns, one on either side of the work, for very high rigidity and precision. The dual column setup is unable to make use of a miter base due to inherent design. Dual column saws are the largest variety of machine bandsaws encountered, to the point where some make use of a rotary table and X axis to perform complex cutting. Automated saws Automatic bandsaws feature preset feed rate, return, fall, part feeding, and part clamping. These are used in production environments where having a machine operator per saw is not practical. One operator can feed and unload many automatic saws. Some automatic saws rely on numerical control to not only cut faster, but to be more precise and perform more complex miter cuts. Common tooth forms Precision blade gives accurate cuts with a smooth finish. Buttress blade provides faster cutting and large chip loads. Claw tooth blade gives additional clearance for fast cuts and soft material. At least two teeth must be in contact with the workpiece at all times to avoid stripping off the teeth. See also Chainsaw Bandsaw box Portable sawmill Band knife Wire saw References Bibliography . Duginske, Mark (1989). The Bandsaw Handbook. Sterling Publishing. . Cutting machines Metalworking cutting tools Saws Woodworking machines