How to Select Router Bits

Posted by John Rennie on

Anyone embarking on a carpentry project knows that router drill bits are imperative for the fashioning of wood and other materials; however, it's not quite as easy to know what router bits do what and how to choose router bits accordingly. 

Here at Rennie Tools, we offer all the basic types of router cutters in the UK, including carbide CNC router bits. Similarly, we have a range of sizes with 2mm router bits, 6mm router bits, and 8mm router bits available online. 

Straight Router Bits

Our straight router bits for UK delivery are an essential to any router toolkit as they quite simply cut straight into the material being used. Therefore, if you need to create a cavity in a material, you will want to select a straight router bit. The length and diameter of the bit will depend on the needs of your project. 

Rabbeting Router Bits

Rabbeting router bits are vital to carpentry projects where the joining of multiple pieces of wood is required. This is because these bits cut shoulders into the edges of work pieces, allowing for a foundation to seamlessly join the pieces together. This is done through a spinning pilot; however, once again, you will need to select the diameter of the bit by assessing your project’s requirements. 

Flush-Trim Router Bits

Flush-trim router bits are used to cut one material’s rim with the side of another. This might include the cutting of a finished surface flush with a substratum or using a shape to produce several duplicate pieces. Typically, flush-trim router bits are guided by a pilot bearing that is either situated at the tip or the base. Usually, the bearing is the same diameter as the cutter. 

Chamfer Router Bits

Chamfer router bits are most often used for decoration as they cut a slope to finish the edges of surfaces. Despite this, they can join multi-dimensional assemblies, too, bearing similarity to rabbeting router bits. Usually, chamfer router bits are utilised for the production of multisided wastebaskets, planters, boxes, and other decorative wooden objects. 

Edge Forming Bits

Like chamfer router bits, edge forming router bits are for the purpose of decorative edging. They come in various shapes and sizes depending on how you want your finish to appear. The shapes range from s-shapes and half circles to quarter circles. Typically, they refine the final touches on edges that have already been formed. These existing edges act as guides for the decorative finish. 

Specialised Bits

Specialised router bits are designed for specific purposes. Examples include spiral upcut router bits, HSS router bits, and engraving router bits. One specific purpose for specialised bits is the shaping of frames within panel-and-frame constructions, such as cabinet doors. Such bits should not be operated using handheld drills due to their large size and should instead be used in table-mounted routers for a safe execution. 

Router Bit Shanks

The shank is the router’s cylinder-shaped bit that goes into the collet. Typically speaking, they do not produce vigorous vibrations and have better stability, all whilst enjoying a longer life and producing a smoother cut. 

Router Bit Cutting Edges

HSS stands for high-speed steel which is one of the most common materials to make router bit cutting edges. Another common material for router bits is carbide which is a compound of carbon and a metal. Carbide cutters tend to be harder than steel, meaning their edges will withstand more use. Despite this, they are more brittle and so should be handled and stored carefully. 

How To Measure Router Bits

Router bits are measured using the shank diameter, overall length, cutting diameter, cutting edge length, radius, and the angle. The shank diameter is calculated through the middle from any position on its circumference. The router’s overall length is determined from the shank’s top to the cutting edge’s bottom. The cutting diameter is quantified from the outside of the cutting edges to the middle of the cutting bit. The length of the cutting edge is calculated from the cutting edge’s top to its bottom. 

Usually, router bits are used to create shapes, meaning the curve will have a radius that also needs to be measured. Despite this, some router bits are designed to give a straight angled cut rather than a smooth curve. In this case, the angle will need to be measured. 

Shop Router Bits with Rennie Tools

Here at Rennie Tools, we have all manner of router bits available for purchase to suit the needs of any project. If you’re unsure about what router bit is best suited to you, our expert team is on hand to help. Contact us via email at or call us on 0161 477 9577 or 07581452424.

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