Tin snips, often referred to as aviation snips, are specialized hand tools engineered for the precise cutting of sheet materials. They were initially developed for the aviation industry to cut aluminum, which gave them their common name. They function by employing a compound leverage mechanism to multiply the force applied by the user, enabling clean cuts through thin metals and other resilient sheeting. This mechanical advantage distinguishes them from standard shears, allowing users to efficiently shape materials that would otherwise be difficult to manage.
Understanding Tin Snips
The design of tin snips centers on the principle of compound leverage, which sets them apart from simple household scissors. This mechanism involves a system of two pivots that amplify the squeezing force from the handles before it reaches the hardened steel jaws. The increased mechanical advantage allows the jaws to shear through materials like metal with far less effort than a direct-acting shear would require.
The tool’s components typically include comfortable, non-slip handles, a fixed pivot point, and precision-ground, serrated jaws. The serrations help grip the material, preventing slippage and ensuring a continuous, controlled cutting line. This robust construction withstands the high stress involved in cutting medium-gauge sheet materials without deforming the blades. The shearing action minimizes burring on the cut edge, which is common with less specialized cutting tools.
Identifying the Types of Snips
Selecting the correct snip depends on the desired cutting path, which is indicated by a standardized color-coding system on the handles. Red-handled snips are designed for left-cutting, executing a clockwise curve. The top blade is positioned on the right, allowing the waste material to curl away to the left side of the cut line, making it easier to follow a pattern that curves left.
Green-handled snips perform the opposite action, engineered for right-cutting, which results in a counter-clockwise curve. The top blade is positioned on the left, causing the waste material to curl away to the right side of the cut line. Using the appropriate curved snips prevents the body of the tool from obstructing the path and maintains the integrity of the finished piece by preventing the metal from buckling along the edge.
Yellow-handled snips, often called straight-cut snips, are used for making long, linear cuts or shallow curves. These shears feature symmetrically aligned blades, allowing them to cut in a straight line without forcing the material to curl significantly. While a straight cut can be achieved with red or green snips, the yellow variant is optimized for maximum efficiency and blade clearance when following an uncurved path.
Essential Uses and Applications
Tin snips are employed across various trades and home improvement projects where thin, rigid materials require shaping or trimming. They are commonly used to manipulate sheet metal, typically handling mild steel up to 24-gauge thickness and stainless steel up to 28-gauge thickness. This capability makes them standard equipment for installing HVAC ductwork, where precise cuts are needed to assemble systems cleanly.
The tools are highly effective for working with softer, non-ferrous metals like aluminum flashing and copper sheeting used in roofing and exterior waterproofing applications. Home improvement projects often rely on snips for cutting wire mesh, metal lathe, and sections of vinyl or aluminum siding panels. The controlled shearing action allows for clean edges, reducing the need for extensive filing or deburring after the cut.
Furthermore, snips are used for trimming metal studs in light-gauge framing and shaping specialized metal roofing elements, such as valley flashing and drip edges. Their utility extends beyond metal, proving useful for managing tough materials like heavy plastic strapping, abrasive paper screens, and thick leather when high leverage is necessary.