Sheet metal shears are a type of tool used to cut sheets of metal, including aluminum, steel, bronze, brass and copper. Despite their name, sheet metal shears are also a popular device for cutting or shaping sheets of plastic. Unlike traditional blades or cutting devices, sheet metal shears have relatively square edges. Regular sharp-edged blades are often not strong enough to cut sheet metal, so the shears have square-edged blades for added strength and durability.
There are many different types of shears available for sheet metal shearing, ranging from small hand-held units to large floor-mounted models. Hand sheet metal shears can be pneumatic or electric to provide added strength and power for cutting thicker or stronger metals. Other hand-operated units resemble large paper cutters, and use a guillotine-type blade to cut thin sheets of metal. Small sets of hand-held tin snips are also sometimes used for simple sheet metal shearing jobs.
For larger projects, floor or bench-mounted units are available. They may be operated using a foot pedal or control panel, and may be electric or pneumatic. Most large floor-mounted sheet metal shears feature a programmable cutting mechanism, which may use either a blade or laser for shearing the metal. Lasers use heat to melt the metal, which results in clean and even cuts. Operators activate the machine using a computerized panel, which allows for precise cutting and shaping.
Sheet metal shears can be either throated or throatless. A throated shear can accommodate only a specific range of sizes, while throatless units can accommodate items of any size. The difference between these two models lies in the design of the machine, and also in how the metal is fed through the cutting mechanism. Some units are designed to cut only straight lines, while others can make angled or curved cuts. Most types of shears are rated up to a specific metal thickness or gauge, and only the strongest and most durable units can be used for heavy-duty projects.
These tools are used in a wide variety of industries, both in manufacturing shops and out in the field. They can be used to cut automotive and aeronautical parts, building materials, or components used in manufacturing and industry. Many builders use some type of sheet metal shears in the field to cut metal roofing panels, siding or heating, ventilation and air conditioning (HVAC) ducts. Sheet metal shears can also be used to perforate, score or forge a series of holes or patterns in sheet metal rather than cutting it completely.