Whereas bits with more flutes can give a smooth cut but they generate more heat and reduce chip evacuation. Lower flute count can achieve a high chip evacuation but after the cut, it leaves a rough surface. Here only two flutes are engaging with the material, it gives enough time and space for the chips to easily escape from the cutting pocket. However, there are special cutters with coatings that only get activated once they reach a certain temperature.īits with two flutes are used for cutting wood and aluminum as they can efficiently cut the material and still keep the bit cool. Heat is a bad thing for most cutters, it reduces the sharpness of your flute and can sometimes be the root cause of a fire in your workspace.

If you generate heat while cutting plastic the plastic will slowly melt and stick to your bit causing all sorts of problems to your milling process.Īs the flute size increases, you have to cut the material a little slower, else it'll generate more heat. While working with plastic, you need a cut pattern that removes as much material as you can but also evacuates it quickly as possible without generating any heat. They are also commonly used in dynamic or high-efficiency machining (HEM).Ĭoatings play a crucial part in the performance of your cutting tool, however, tool geometry is just as important to be successful.In the case of end mills, they have spiral-shaped flutes which can effectively mill and plunge through the work material with a screw-like action.īits with a single flute are specifically designed to cut on plastics, HDPE, and acrylic. Six Flute and Above: These are finisher endmills that produce a very fine finish.

These are better suited for high-efficiency milling and hard materials. These are most often used when cutting ferrous materials.įive Flute: Have smaller flute spacing than four-flute endmills allowing for more strength than four-flute endmills. They have less flute space than the 3-flute endmill and produce smaller chips. Used for ferrous and non-ferrous materials.įour Flute: Stronger than the three-flute endmill allowing for faster feed rates.

Three Flute: The same space between flutes as the two-flute endmill, but are stronger. Two Flute: Used for high-volume removal in slotting and pocketing non-ferrous materials. Single Flute: Used for high-speed machining of high-volume material removal often in plastics or CFRP. A higher number of flutes will increase the strength of the tool and are better suited for cutting harder materials. A small number of flutes allow for more chip space allowing for faster material removal, but make the tool weaker. It is a cavity that spirals along the axis of the tool body. By creating an endmill with unequal pitch some more some less than 90 degrees, the cutting forces are changed which results in reduced vibration, higher feed rates and better part finishes.įlutes are the cutting surface of the body of the tool. On a standard 4-flute tool the cutting edges would be 90 degrees apart. Variable Pitch: Refers to cutting edge spacing that is unequal. Variable Helix: A variable helix endmill utilizes unequal flute spacing to reduce harmonics which can greatly extend tool life and improve part finish. More flutes increase the tool strength but reduce the cutting depth for a smoother cut better suited for harder materials.

Fewer flutes allow for larger chips and a deeper cut depth, but are weaker and best suited for plastics and aluminum. Helix Angle: The angle measured from the centerline of the tool and a straight line tangent along the cutting edge.įlutes: The spiraled cutting grooves in the tool. Length Below Shank: Also called the reach, is the length from the necked portion to the end of the cutting end of the tool. Length of Cut/Flute Length: The functional cutting depth with the tool in the axial orientation. Overall Length: The total length of the tool between both axial ends. Shank Diameter: The width of the shank that is held in the toolholder. Cutter Diameter: The diameter of the theoretical circle formed by the cutting edges as the tool rotates.

End mill bits