CNC routers are powerful machines that have numerous possibilities for creating intricate designs with precision and accuracy. However, it is the bit that plays the trick, determining the quality of the finished products. CNC router bits are capable of finishing various jobs, such as engraving, cutting, pocketing, milling, grooving, and drilling. With so many bits available on the market, it can be frustrating and confusing to choose the right one for your job. There are too many factors to consider when selecting. That’s the reason why we’ll provide a complete and basic guide to CNC router bits, covering everything from the types of CNC router bits to materials, cut types, and applications. Whether you’re a pro or a beginner, this guide can help you select the right CNC bit for your project.

Materials

There are four types of CNC router bits when it comes to materials: high-speed steel (HSS), carbide-tipped (TCT), solid carbide, and polycrystalline diamond (PCD).

1. High-speed steel (HSS)

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Due to the relatively shorter service life compared to carbide, HSS router bits need frequent sharpening by diamond hones. However, HSS is heat-resistant and less likely to break. CNC router bits made from HSS are ideal for cutting softwood and lightweight plastics.

2. Carbide-tipped (TCT)

The cutting edges of TCT router bits are made from tungsten carbide, featuring outstanding sharpness and durability. Therefore, they require no regular sharpening. Although TCT CNC router bits are slightly expensive, they are low maintenance and result in improved productivity.

3. Solid carbide

CNC router bits made of solid carbide are more expensive than HSS and TCT. They are even more wear-resistant and have much better hardness. Solid carbide router bits have better performance with harder materials like hardwood, hard plastics, and soft metals. However, they are brittle and more like to break during operation, thus requiring extra care when using.

4. Polycrystalline diamond (PCD)

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PCD router bits are made from diamond particles blended onto carbide substrates to realize extreme hardness and abrasive resistance. CNC router bits made from PCD or PCBN (polycrystalline cubic boron nitride) are perfect for cutting hard metals.

Tool geometry

CNC router bits with different tool geometry are designed for different purposes.

1. Flat-end

As the name implies, flat-end CNC router bits are designed with a flat bottom, suitable for cutting, milling, grooving, and engraving. There are two types of flat-end CNC bits: spiral bits and straight bits. Straight CNC router bits are mainly ideal for cutting wood, whereas spiral CNC bits are more suitable for processing plastics and metals. Spiral bits have three cut types: upcut, downcut, and compression cut. We’ll discuss this later.

2. Ball-end

Ball-end CNC router bits are specifically designed for grooving and engraving curved surfaces thanks to their rounded tips. They can create a very smooth finish. Mostly, a ball-end CNC router bit works perfectly with softwood, but it is capable of processing all materials. Additionally, they can also be used to produce 3D carvings.

3. V-groove

Typically, V-groove CNC router bits have a V-shaped tip with an angle varying from 30-degree to 120-degree. They are frequently used for engraving v-shaped cuts on wood panels, especially hardwood. V-groove bits with smaller diameters and angles are more appropriate for intricate and detailed cuts whilst large diameters and angles can create bigger details.

4. Profiling and molding

Profiling and molding CNC router bits are ideal for producing a various range of profiles and moldings on different materials.

Cut types

As we mentioned above, spiral CNC router bits have three cut types: upcut, downcut, and compression cut.

1. Upcut

Upcut CNC bits remove chips and dust upward during operation, so they leave a ragged top surface and a clean bottom surface. They are recommended for grooving and slotting purposes. If you need a clean bottom surface of a workpiece, an upcut spiral bit is your choice.

2. Downcut

Contrary to upcut bits, downcut CNC bits evacuate chips downward, thus creating a clean top surface. They are recommended for cutting thin, flexible materials instead of thick materials. When a clean finish on the top is required, a downcut CNC router bit is used.

3. Compression cut

Compression bits are capable of leaving clean surfaces both on the top and the bottom due to the combination of both upcut and downcut. Compression bits are more expensive than the other two types because of the complex design. When it comes to cutting materials like plywood, veneer, and laminates, a compression bit is a perfect choice to produce clean surfaces on both sides.

Things to consider

When selecting the right CNC router bit, there are several things to take into account. The most critical factors are cutting materials and project types.

1. Materials

Cutting materials matter a lot in selecting the right CNC router bit. Different types of CNC bits are designed for cutting different materials. Choosing the wrong bit can result in poor performance, or even damage the bit. Generally, hard materials such as stone or hard metal require CNC bits with higher hardness such as diamond bits. While soft materials such as softwood may require carbide bits or HSS bits. The following are some suggestions for your reference.

• Intricate and detailed carving, and engraving projects require ball-end CNC bits;
• Laminated or plywood or veneered materials should be cut by compression bits;
• HSS bits are perfect for soft materials such as softwood;
• Hard materials like hardwood, and soft metals are recommended to be processed by TCT bits or solid carbide bits;
• When working with very hard materials like hard metals, glass, or stone, it is advisable to use PCD bits.

2. Projects

Selecting the right CNC router bit also depends on the project type you’re working on. For example, lettering or sign-making requires V-groove bits. Complex 3D carving projects require ball-end bits.

Konetool, an ISO-certified supplier, has been dedicated to supplying CNC router bits for over a decade. If you’re looking for a reliable supplier of router bits for your business, please don’t hesitate to contact us or request our router bit catalog.

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