As the most commonly used type of router bit, straight router bits are basic and essential for your woodworking projects due to their versatility. They are mainly used for making grooves, dados, notches, mortises, inlays, etc.
If we cut along the grain of the wood, we can create grooves. While cutting against the grain of the wood we can create the dado. These grooves or dadoes are often used for wood joints.
Additionally, for decorative purposes, straight mills can hollow out areas for decorative inlays.
Spiral router bits are mainly used in CNC milling machines for milling. Their shear edges have a better finish than standard straight mills.
The upward-cutting auger bit leaves a perfect cut on the top of the workpiece. A downcut auger bit will leave a clean cut on the bottom. The compression bit creates a nice finish on both sides.
Standard straight router bits get the job done perfectly for less. However, spiral router bits are becoming increasingly popular due to their ability to maintain a cleaner cut. So under what circumstances do we need to upgrade to a spiral milling cutter?
CUTTING EFFECT
Spiral drill bits have angled cutting edges that continuously cut through the workpiece, leaving cleaner cuts than straight drill bits, especially on veneer plywood.
Both upper and lower cuts are available. Upcut augers remove chips upward, leaving a clean edge on the bottom; while downcut augers do the opposite.
Compression drill bits leave clean edges on the top, bottom, and middle of the workpiece. So, if you are working with a quality piece of veneer, choose a compression auger bit to get the job done.
When making wide cuts, a straight drill bit makes sense, as it can cut a much larger diameter than a spiral drill bit.
Since the cutting diameter of a spiral mill is usually the same as or smaller than its shank, it is difficult to find a spiral drill bit with a cutting diameter larger than 1/2 inch, which is nearly the largest shank of a milling cutter bit.
However, this is not the case with straight drill bits. Standard straight drill bits are available with cutting diameters up to 2 inches and a variety of cutting lengths. If your oak requires wide cuts or multiple cutting lengths, a straight drill bit will meet your needs.
WORKPIECE FIT
The tip of an spiral bit is similar to a drill bit, with the tips of the grooves ground. Therefore, we can insert the spiral mill directly into the board from the surface.
However, due to the design of the straight milling drill tip, no cutting occurs during plunge milling. If we try to cut in with a straight drill, the workpiece will be scratched.
When using a straight mill, you can still make plunge cuts or create mortises, but we need to clean the mill during the process. It is highly recommended to dive less than an inch.
COST CONSIDERATIONS
Although spiral drills provide a better cut than straight drills, they won’t fit everyone’s budget.
Due to different manufacturing processes and raw material consumption, spiral drill bits are usually sold at a much higher price than straight drill bits.
Meanwhile, the carbide thickness of the straight drill allows for up to five sharpenings. However, due to the design of the drill, few companies are able to grind spiral drill bits to factory standards.
The good news is that spiral mill bits stay sharp longer.
When it comes to spiral milling cutters vs. straight milling cutters, there is no absolute winner. Remember to choose the right drill bit that will work best for your project.
Dehuai Technology provides a full range of milling cutters, including single-edged milling cutters, double-edged milling cutters and extra-long milling cutters. If necessary, please feel free to contact us.
