What Are Lewis Auger Bits and What Are They For?

One of the activities for those involved in maintenance and construction work: drilling wood. To do this, you can use various types of tools and blades. Among these solutions we also have Lewis auger bits: you recognize them because they have a particular shape.

The bit in question looks like a metal band that wraps around itself. It's not common to find this type of bits for wood in the toolbox, usually the standard solutions are enough to complete the work. At most, for larger holes you use hole saws for wood. But if you want to complete your work in the best possible way, you should also consider using Lewis-type drill bits: they are not superfluous in some cases, here's how to evaluate them.

What are Lewis-Type Drill Bits?

These bits for working wood - also known as Auger bits or Lewis spiral bits - are drilling tools used to create deep, precise and clean holes, maintaining a perfectly straight trajectory thanks to the structure.

Unlike classic bits for drilling wood, which look like simple cylinders with sharpened grooves, the Lewis bit has a very ingenious structure. It was designed specifically for carpentry work, to make its way through wood without particular effort.

This is precisely because of its ability to adopt the shape of spiral drilling tools. An important detail: don't confuse the Lewis bit with the tool of the same name - the auger, namely - which is a tool to make small holes without a drill.

How are Auger-Type Drill Bits Constructed?

There are several elements that characterize Lewis bits. The first is at the top, at the top there's a small threaded structure similar to a wood screw that bites the wood and begins to pull. So you don't have to push yourself, the bit activates the automatic pilot to drill the wood with precision. Immediately after you find two small sharp wings that trace a circle before the blade begins to dig.

This serves to cut the fibers cleanly, preventing the edge from fraying or splitting. Following this we have the blade that excavates the material, lifting thick chips as if it were a circular planer. The body of this bit has a solid central core composed of a spiral that rotates like a helical staircase, and this solution makes the difference with a normal wood drill bit.

Why Choose a Bit Like This for Wood?

There are various bits suitable for drilling wood that resemble the classic formula of helical HSS. First and foremost, Lewis auger models are very precise on wood: where you place the bit, it stays there and continues to advance even if the pressure is minimal. Whereas with the standard bit if you stop pushing the work stops. But that's not the fundamental advantage, or at least not the only one.

These solutions are perfect for making very deep holes in wood with perfect edges: it's a true auger. The spiral manages to throw out large quantities of chips without ever stopping, executing a 30 cm deep hole in a single pass.

In summary, you can use a normal bit to work a board or a small surface. But if you need to drill through a beam very deeply, and you need to execute a perfectly perpendicular and deep hole without effort, this is the solution to choose.