End mills can be classified based on the number of flutes, helix angle, shapes, materials, coating, and more. Here we talk about some common types of end mills.
1. End mills in different shapes
– Ball nose end mill: with a radius at the bottom which makes for a greater surface finish, produces a rounded pass, ideal for 3D contour work, shallow slotting, pocketing, and contouring applications.
– V-bits: with small angles and tips, produce a V-shaped pass, used for engraving, narrow cuts, and small, delicate engraving of lettering and lines, particularly for making signs, it’s also available for exceptionally sharp edges. The v-bit end mill comes in two forms- 60°or 90°V-bit.
– Fishtail end mill: with cutting edges on one end, which may be much thinner than the other end, fishtail end mills can plunge directly into your material and produce a flat surface, prevent any splintering or breakout, create clean edges on thin material and make pockets with flat bottoms, suitable for plunge routing and producing precise contours, like signs. With fishtail end mills, you can also have nice square corners at the bottom of any inset section of geometry.
– Square end mill: also known as flat end mills, are general-purpose mills that generate flat-surfaced cuts with perfect 90° corners in the workpiece, involves milling operations like side milling, face milling, and more. Square endmills can be used in the roughing or finishing stage.
– Bull-nose end mills: also called corner radius end mills, this type of cutter is a combination of fishtail and ball-nose, also a flat bottom but with rounded corners. Bull-nose end mills are often used to mill molds (plastic injection molds, die cast molds, etc.)
2. End mills in different number of flutes
The spiral-shaped cutting teeth on the end mill are flutes, which offer an empty path for cutting chip removal during the machining process. End mills available in 2, 3, or 4 flutes, 2 and 4 flutes end mill are more common. More flutes create a smoother surface finish, while fewer flutes are best at chip clearing and keep heat from building up.
– 2 Flute end Mill: suitable to work with wood and aluminum because they produce large chips
– 4 Flute end Mill: used to machine most other materials, cut harder materials than 2 flutes
3. End mills in different materials
– High-speed steel (HSS): cheaper than carbide tools but dull faster as well
– Carbide: is brittle and can shatter, provide better wear resistance and toughness. Carbide end mills are extremely heat-resistant and used for high-speed applications on some of the hardest materials.
– Solid Carbide end mills: considerably harder, rigid, and more wear-resistant than other types.
Endmills also come in different coatings and helix angles.