SURFACING BITS for cnc routers
EVERYTHING YOU NEED TO KNOW
what is a surfacing bit
Surfacing bits are one of the most important cutting tools when it comes to CNC routers.
It is a type of CNC router woodworking cutting tool that is used to create a smooth, flat, and even surface on a workpiece, to flatten slabs, and most importantly, to level a spoilboard (the surface your CNC project will be held down to).
These bits can be used in the final stages of a CNC router woodworking project, but are more commonly used first.
Surfacing bits are designed with a wide, flat cutting edge and a steep cutting angle, which helps to produce a smooth, even finish on the surface of the workpiece. They can be used to remove small amounts of material or take deeper cuts when needed.
Surfacing bits cutting tips are made from tungsten-carbide which is welded onto a high-carbon steel body and are available in a range of sizes and shapes to suit different types of CNC routers and materials.
The surfacing bits on this page are for CNC router woodworking projects.
Not All Surfacing Bits Are The Same
The 'ultra-smooth cut' series surfacing bits from idc woodcraft
Surfacing bits for CNC routers are typically made from the same standards, regardless of who provides them. This means you are getting roughly the same tool, no matter where you get your surfacing bit from.
We at IDC Woodcraft never settle for ‘standard’, so we looked at this and realized there is room for improvement to get better finishes from your surfacing bits. So we completely redesigned the cutting geometry to accomplish this.
The result is the Ultra-Smooth Cut series surfacing bits. As an unexpected bonus, these surfacing bits can run at higher feeds and speeds and have a significantly longer life.
surfacing bit feeds and speeds for cnc routers
Surfacing bit feeds and speeds are the settings you will use to get the optimal performance and longest life out of the cutting tool.
Feeds refers to the rate the surfacing bit is moving across the material. Speed is how fast it is spinning (rpm). The combination of these two factors affects the quality of the cut and the speed of the router.
The 1-inch surfacing bit shown here is the most popular surfacing bit for benchtop CNC routers such as Longmill MK2, Shapeoko & Next Wave Shark. This particular bit from IDC Woodcraft is an advanced design from standard 3-flute surfacing bits. To learn about these differences, watch this video.
- Speed (rpm): 9000-12000
- Feed: 120-150 ipm
- Depth of cut: 0.1”
- Stepover: 70-80%
- Item #SU-10
3/4-inch Ultra-Smooth Cut surfacing bit with 1/8 shank
This surfacing bit is designed for smaller desktop CNC routers such as 3018 series routers (Yorahome, Sainsmart, Genmitsu, etc). It is the only surfacing bit that exists with a 1/8″ shank.
- Speed (rpm): 8000-12000
- Feed: 80-100 ipm
- Depth of cut: 0.05”
- Stepover: 70%
- Item #SU-34
Also used on benchtop units, the 1-1/2 surfacing bit is designed to cut a much broader area which decreases run-time substantially and provides the smoothest surface. This is designed for benchtop CNC routers and floor models (Longmill, Shapeoko, Next Wave Shark, etc)
- Speed (rpm): 12000
- Feed: 120-150 ipm
- Depth of cut: 0.07”
- Stepover: 85-90%
- Item #SU-15
Is a Surfacing Bit an endmill?
A surfacing bit and an end mill are both types of cutting tools used in machining. Technically, a surfacing bit is an endmill and is set up as one in CNC router design software. However, a surfacing bit is designed differently.
A surfacing bit is used to smooth and level out the surface of a CNC router spoilboard, and is used for slab flattening. It typically has a wider, flatter tip than other types of cutters, and can be used to make smooth, even cuts across a surface.
An end mill, on the other hand, is a type of cutter that is used to create pockets, slots, and other features in a piece of material. Endmills have flutes, or cutting edges that are long, and allow for deep cutting. this is called the flute length, or cutting depth. The flute lengths of surfacing bits are much shorter.
Another difference is the bottom-cutting capability. A surfacing bit does not have cutting edges along he full length of the bottom as you might find on endmills. This means you cannot plunge into the material as you would with an endmill. Rather, you would ‘ramp’ into the cut or start from the side of the material and move in from the side.
One other difference is the cutting edges are either removable (insert style) or have the cutting tips welded (brazed) to a central body. This is done to keep costs down since the carbide material used as the cutting edge is an expensive material.
It is necessary to have both surfacing bits and endmills in your CNC router cutting tool arsenal.