Duct Bending Flange Tools

Snips

• Snips are basically heavy pairs of scissors that can cut materials such as plastic, vinyl, rubber and metal -- including sheet metal. You can use snips to cut through a duct when you're doing flange work. A deluxe set of snips, like those produced by Irwin, are also comfortable to use. Irwin snips, in fact, come equipped with textured grips.

Crimpers

• Crimpers are duct-bending tools that can decrease the diameter of an air-conditioning duct. They essentially squeeze the edge of the duct, compressing it so it will take up less room (as opposed to cutting through the duct, like snips do). An example of a crimper is the one produced by Malco, which includes contours that are ergonomically designed so as not to slip while you're working, as well as a simple latch motion that requires only one hand to operate.

Seaming Tools

• Where crimpers can squash the edge of a duct, seaming tools can actually bend the edge of a duct and shape it the way you want to. Most seaming tools, or seamers, look like a pair of tongs. A 1983 patent for a typical pair of seamers describes a driving lever that's elongated, a flat plate standing upright and attached to this driving lever, and a head attached to that plate. The head is used for striking the duct; the duct can then be grasped and twisted by the two levers being squeezed together.

Notching Tools

• The job of the notching tools is to make indentations, or "notches," in the edge of the duct. Many notching tools are shaped like the letter 'V,' and they function kind of like giant, heavy-duty paper hole-punchers. The HTP notching tool, for example, is used for welding. The notches that this tool creates admit the metal that's welded in, and the resulting panel will be stronger than it would have been had there been no notches.