Need a tool attachment that can cut, shape, grind and remove imperfections in any material? Then, look no further than carbide burrs. These are tool bits that fit die grinders, rotary tools, engravers and micro drills, and are used in hundreds of varied applications, ranging from tooling, welding, carpentry and woodworking, dentistry, engraving, and DIY and hobbyist tasks that require fast and precise stock material removal.
What Are Carbide Burrs?
Carbide burrs go by a few names. Whether you’re dealing with a carbide burr tool bit, die grinder bit, burr cutter, or rotary burr, this is the same thing. The different names imply they’re used with fast-spinning rotary tools that allow the bits to cut, grind, shape, smooth, carve and deburr a huge range of materials, from harder metals to soft plastics. The bits also come in different shapes to get the cut you need and in a range of sizes to fit the appropriate tools and the application.
How Do They Differ From Regular Bits?
This is not your regular drill bit or tool attachment made of high-speed steel, or HSS. What makes these bits exceptionally efficient is how they’re made.
Burrs consist of tungsten carbide, a metal-ceramic hybrid made of equal parts tungsten and carbon, and some cobalt thrown in as a binder. It is three times stronger than regular tool steel, has minimal wear even when cutting tough metals, and keeps its form under higher temperatures when bits are cut into harder substances and at higher tool RPMs. The material is so hard that it needs diamond-coated tooling bits to shape and cut them to size.
Where Are They Used?
If you work with carbon and stainless steel, cast iron, and other ferrous metals, then carbide burrs are what you need to cut and enlarge holes, remove burrs and rust buildup, get clean welds or precisely shape workpieces to the desired form. The hardness of the carbide burr tool is what makes this possible. Not only can you work with thicker metals, but the burrs also leave clean finishes, which are necessary for further fabrication or when adding fasteners.
The bits work equally well in non-ferrous metals, particularly aluminium, but also in copper and copper alloys (bronze and brass), lead, nickel, tin and zinc. And you’ll regularly see them in woodworking shops, where they easily shape or smooth both hard and soft woods.
Moreover, burrs can cut through any type of plastic, easily eat into stones and gems, and engrave, shape, smooth and cut gold and silver in jewellery pieces. They’re one of the first tools dentists use when dealing with tooth decay.
Choosing Between Single and Double-Cut Burr Cutters
The wide scope of uses means burrs in different cutting profiles. Here, the basic distinction is between single and double-cut bits. Single-cut carbide burrs have a single-cutting profile spiralling from top to bottom. This is ideal for quick stock removal in thicker materials, particularly in harder metals, general drilling, milling and boring purposes, as well as cleaning and smoothing tasks such as removing excessive weld spatter or rust pockets. The burrs produce larger chips and clear more material with each rotation, but they won’t provide a super-smooth surface.
This is the domain of double-cut (or diamond-cut) carbide burrs. They have two intersecting sets of flutes, ideal for surface cleaning, fine finishing and smoothing in a range of materials and workpieces, but more so with softer metals like aluminium. The burrs produce cleaner results with smaller chips and are also used in light milling and deburring tasks.
Why Shapes and Sizes Matter
Shapes determine the type of cut this tool bit can produce, while sizes dictate the tools they’re used with and general operating speeds.
Choose ball or spherical burrs if you need concave cuts or want to hollow out a defined area. This shape is popular both in wood and stone carving as well as general engraving, specifically when attached to smaller rotary drills. Pointed or round tree burrs are used when working edges, in hard-to-reach spaces, or getting acute angles. Inverted-cone die grinder bits are perfect for V-cuts and when fitting bolts and screws in chamfered edges, while cylindrical types are mainly used in smoothing and deburring flat surfaces.
There are also oval and flame-shaped bits for contouring and end milling, countersinking types, and pointed cone burrs for acute angles. If you need versatility and a variety of cuts, consider getting packaged sets in sizes appropriate for the application and tool.
The Range of Carbide Burr Sizes
Sizes refer to the overall diameter of the cutting head. This can be either in metrical or imperial units. Common sizes range from 1.6 to 25mm or 1/16 to 1″. More common are 3mm (1/8″), 6mm (1/4″) and 12mm (1/2″) variants, particularly when working with metals and wood.
Manufacturers also state shank sizes to fit chuck jaws or collets. This refers to shank diameter, but also lengths where there’s the need for work on areas that are difficult to get to. Here look at 1.6mm or 1/16″ shank diameters for Dremel drills, dentist drills, engravers and micro tools, to 16mm shanks in bigger tools.
Operating Speeds
The speeds at which the burrs are used depend on the tool they’re attached to, the carbide burr size and the material you’re working on. Bits used in dentist drills, for instance, can reach 180000 RPMs, but this number steadily decreases as the cutting tools get bigger and materials harder. Most top out at around 40000 RPMs, but those commonly seen in die grinders average between 10 and 20 20,000 revolutions.
It’s recommended to start with slower speeds to avoid damage to both the burr and workpiece, and steadily increase that to a safe working speed. When dealing with any kind of material, also keep in mind that chips of any size can be dangerous, so always wear the right protective gear.
Final Considerations
Choose carbide burrs if you need long-lasting tool attachments that easily cut, grind, smooth and get the desired results in a range of materials. Bits can be had for numerous tools, are sold in varying shapes and sizes and can work on soft, hard or very hard materials. Look for packaged sets in varying shapes if you’re after versatility in more than one task, and observe burr sizes for precise and consistent outcomes.
