What Is A Manual Nibbler?

What Is A Nibbler?

The Manual Nibbler is the kind of tool you don’t think about until you really need it. I remember my first time using one and cutting through steel like it was nothing.

The nibbler is a tool that cuts through sheet metal. Using a nibbler creates straight, even cuts, with minimal distortion of the sheet metal. The nibbler accomplishes these cuts with an upward blade that punches through the sheet metal.

The hand nibbler can be a powerful tool to keep on hand and is a staple item in shops that frequently cut sheet metal.  They can cut a variety of material, but have their limitations as well. Whether you should use a nibbler and which type of nibbler you need will depend on your project.

How Does A Nibbler Work?

Nibblers work by applying force with a single blade, typically upward. There are tracks on either side of the blade that create a narrow channel. When the blade pushes the material through the channel, it removes a small bit of metal.

The combination of the force from the blade and the hard edge of the channels is how the hand nibbler achieves a cut with little to no distortion. This is also why the cuts made by the nibbler are typically much smaller than what you get with shears or snips.

The nibbler leaves behind a narrow channel approximately 6mm wide, and is referred to as a ‘kerf.’ A kerf is a channel left behind by a saw or blade, and is measured by the width of the saw blade.

The actual size of the kerf depends on several factors. The width of the blade and channel, the amount of material pulled out, and whether or not the blade wobbles when it cuts will all affect the size of the kerf. If the kerf from your hand nibbler varies in width, this could be due to a loose blade or poor quality nibbler.

Types Of Nibblers

Sheet metal nibblers have been around for generations, and the technology has remained mostly the same.  A few companies such as Adel continue producing very conventional style nibblers. Bessey, on the other hand, invested in rethinking the nibbler from the ground up.

Punch And Die Nibblers

This conventional nibbler from Adel, known as the ‘punch and die’ nibbler, is very near the original manual nibbler design. Conventional nibblers are held perpendicular and below the sheet metal that is being cut. The mechanics apply pressure from the top down, ‘nibbling’ into the sheet metal a small bit at a time. This is where the tool got its name.

The nibbling action of the conventional nibbler creates shards of metal as it is used. Each ‘nibble’ takes out a small chunk of sheet metal when you apply pressure, and ejects that shard as you release. Because of this, the conventional nibbler will typically have a plastic shield to guard you against the debris.

Conventional nibblers apply all of the pressure of its bite in one motion. This requires a significant amount of force and strength, while also being very stressful on the nibbler’s blade.

Nibbler Shears

Nibbler Shears, such as Bessey’s super nibbler is the most modern version of a manual nibbler available today. Unlike the conventional nibbler which must be held perpendicular to the sheet metal, the super nibbler is held parallel. The cut is made as the handles are squeezed together. This is a very intuitive design similar to snips or shears, though the super nibbler still uses a single blade.

The super nibbler is versatile enough to operate from an upward or downward position so you can have the blade cutting in either direction. The default state, ergonomically, is to have the blade cutting upward.

Where the conventional nibbler applies downward force, the super nibbler has a blade at the bottom and cuts upward. There is still a shield in place to protect you from shards that break away.  

Though it does have a small shield to protect from shards, the design of the Bessey doesn’t typically create shards. As the blade bunches upward the sheet metal is punched against two parallel tracks. The waste metal is pushed through the 3-6mm gap, and spirals as you cut.

The super nibbler is several inches longer than other nibblers as well, even those which are shaped more like shears than traditional nibblers.  The more extended design gives the user more leverage, allowing you to make the same cuts with less force.

Finally, the modified design of the super nibbler applies the pressure slowly over the blade. This also decreases the amount of force required to use the tool. Because there is less force involved and it is applied more slowly, the blade on the super nibbler is subject to less stress while cutting.

Unfortunately, the Bessey Super Nibbler has been discontinued and can be slightly tricky to find.

Which Nibbler You Should Use

 Hand nibblers are very commonly used to cut through a variety of sheet metal. They are typically rated to cut a maximum 18 gauge sheet metal. You can also use hand nibblers to cut through copper, PVC, and aluminum.

Nibblers are common tools when doing bodywork on vehicles, mainly when working on door pieces or window frames.  They are also common tools for roofers, welders, and other craftsmen who work with stiff, unbending material.

You will want to use conventional hand nibblers in some situations, and nibbler shears in others. There are also scenarios where nibblers are not the best tool for the job, in which case you will want a pair of shears or snips. However, if your goal is to minimize distortion, nibblers are typically the best tool for the job.

Conventional hand nibblers are particularly handy when making an inside cut on your sheet metal. With a starting hole of only 8.5mm in diameter, you can finesse the nibbler into the hole and create the cut. This would be impossible to accomplish with shears or snips.

Another situation where conventional hand nibblers are the best tool is when making intricate cuts and shapes.  The conventional nibbler can cut into a corner with much more ease, and create much more precise small cuts in several directions.

Nibbler shears, on the other hand, are particularly useful when making long straight cuts on sheet metal. If you are starting on the corner, you may want to use a conventional nibbler for the first cut and then finish the job with the nibbler shears.

One of the biggest appeals of the nibbler is the ability to create cuts without distortion. Distortion can be anything from bending to cracking, all of which can give undesired results.

Because nibblers take approximately 6mm out of the material you are cutting, nibblers may not be a good option when cutting material to size. For example, if you have a sheet of metal that you need to cut directly in half and you cut it with nibblers, you will lose about 3mm on each finished sheet.

Nibblers Vs Snips

Nibblers and snips can look remarkably similar but have one key difference.  Snips, which are also referred to just as ‘shears,’ are used generally for the same purpose as nibblers. Though both tools exist for cutting sheet metal and other rigid materials, snips have two blades where the nibbler has only one. Dual-bladed snips do not use a track to punch out material, and therefore will not create a kerf while cutting. This means the material cut will not lose 3mm of material on either side like it would when you use a nibbler.

Another difference is that snips cannot easily turn corners. If you are making an extended rounded cut, snips may work exceptionally well. However, if you are making angled cuts or sharp corners, the snips will not fare well.

Shears excel for making long straight edge cuts long gradual curved cuts reasonably quickly. Cutting a curve tighter than a circle with an 8’’ radius may start to get tricky, but curves 8’’ or bigger should be handled with no problem.

If you use these tools with even semi-regularity, it’s a good idea to keep a variety on hand. Owning a traditional nibbler, a pair of nibbler shears and a pair of snips will cover all of your bases. That way you will have what you need whether punching out a hole, making a small corner cut or rounding a piece of sheet metal.

Where To Buy

Manual nibblers are becoming increasingly harder to find as the powered jigsaw-like version becomes more and more popular. Your mileage may vary, but in my search for a new nibbler I struck out at Home Depot, Lowes and Ace Hardware.

Combine that with Bessey’s discontinuation of their super nibbler, and you may find it surprisingly challenging to shop for such a simple tool. However, there are quality options still available.

For conventional nibblers, Aircraft Spruce and Specialty sells the Adel Hand Nibbling Tool. This is a 100% metal tool, with a rock solid, durable construction. There are very few companies still manufacturing this tool, and fewer who do so with such exceptional quality and sturdiness.

If you will be cutting rigid materials frequently, you should keep a pair of nibbler shears in your shop as well. If you’re in the market for a pair of nibbler shears, Eastwood tools are very reliable. Specifically, the Supercoup NR1 nibbler with an anvil cut off is extremely comfortable and easy to use.

The anvil cut off feature will automatically snap off the curled up waste material when you finish your cut. The Supercoup NR1 is constructed entirely of steel and hardened steel jaws.

There are a few reviews that mention the blade snapping off. You can avoid this issue by sticking to material within the gauge ratings on the website. With the right tool, and careful, deliberate pressure, I have had absolutely zero issues.

Like all tools, what you should buy depends mostly on your budget and the type of projects that you plan to tackle. You may never work with large sheets of metal, but only smaller pieces. In that case, you could easily get by without ever needing the nibbler shears.  But it’s always better to have it and not need it than to need it and not have it!

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