Roofers who work with sheet metal require not only specialized skills and experience to be effective, but also specialized tools, in order to excel in their craft. In sheet metal roofing, this applies to tools like hammers and sheet metal benders, as well as heavy duty sheet metal cutters.
Sheet metal cutters are used to perform just that service – cutting sheet metal. While it isn’t rocket science, it’s not as simple as picking up a pair of sheet metal shears or tin snips (also called aviation snips) and making a cut through stainless steel sheeting the way you would through construction paper. For one thing, it requires more concentrated force, and for another, it requires the right set of shears.
For example, any pair of sheet metal shears should be able to cut a straight line through sheet metal medium; some pairs can cut not only straight but also along a curve, either to the right or to the left, but not both.
This is only one thing that comes along with the territory – shears can also cause deformation along the edge of a cut through sheet metal.
If this is something you have had an issue with in the past, perhaps the solution lies in an interesting tool called a nibbler.
How Shears Work
To understand this issue, you need to understand how shears work, at least on a basic level. Luckily, as we said, this isn’t rocket science. Simple shears consist of two levers and a fulcrum joined at the middle. Two ends of the shears are reserved for handles, and the other two are crafted into jaws. These jaws concentrate the force from your hands into the edge of the jaws of the shears and literally force them through the sheet metal, creating a cut.
This is an effective method, but it is not perfect.
A Sheet Metal Cutter: The Problem
If you have had problems with edge deformation while cutting through sheet metal with shears, then the problem lies with “shear stress” which can cause “shear deformation.”
Because shears use compounded directional force to separate sheet metal, the sheet metal itself is under a lot of stress at the point where the jaws of the shears meet it. The sheet metal does not want to be forced apart, and the alloy is subjected to differential levels of stress at a very small level where it is in contact with the shear’s jaws. This is the shear stress above that causes the shear deformation in question.
What it looks like is a metal edge that is wavy or irregular, and one that is not smooth. Well, the thing about shears is that although the edge of the cut itself may be nearly finished and not jagged, it also might have undulations which are unsightly or impractical.
If this has been a problem for you in the past, a nibbler might be the perfect sheet metal cutter for your needs.
How a Nibbler Works
Nibblers do not work as fast as some shears, but they do produce edges along cut sheet metal that are not deformed, warped or wavy. This is due to the principle by which they operate.
Nibblers also cut through sheet metal like shears, but unlike shears, they do not operate via the same mechanical principles. Instead, the nibbler actually cuts away a thin strip of metal from the sheet metal medium. Somewhat similarly to a saw, a nibbler produces a narrow kerf, whereas shears do not.
Because of this, nibblers are able to produce edges that are free of waviness, irregularity and distortion. In addition, nibblers are able to handle angles, tight turns, recesses, and curved cuts much more easily than shears.
After using a nibbler, the edge along the cut will be rough because of the small chips that were taken out of it by the tool, but this can be folded or finished according to the prescription of the job. In short, if you need a tool that will allow you to make precise cuts without distorting the edge of the sheet metal, a nibbler might be your best bet for deliberate, controlled cutting.
Call Us for More Information
If you want to learn more about the principles of operation behind sheet metal cutting tools like shears or nibblers, don’t be a stranger. For over 150 years, we’ve been providing high quality hand tools and peerless customer service from our location in Old City, Philadelphia – and we still do the same today.
Give us a call even if you just want some recommendations or suggestions. We don’t just sell the stuff – we know the stuff. Anytime you have any questions about our products – how they work, where they can be useful, or what to use – get on the phone with us at 888-847-3456 and we’ll help you out.