Square End Mills or Flat End Mills
Square end milling cutters are also known as a "flat end mills". The corners of these mills are sharp and generate a 90° angle. They can be single end or double end and they can be made from solid carbide or various compositions of high speed steel. Carbide square end mills are the most productive.
They can be general purpose or high perfomance geometries. They can be used used for plunging, grooving, side milling, face milling, and counter boring. These are the most popular milling cutters in the industry. They are available in a wide variety of diameter sizes.
Square end mills have a square nose and are rotated against a piece of stock to create a flat-bottomed groove with 90° inside corners in milling tasks. Also called square-nose end mills, they are used for counterboring, side and face milling, and milling square shoulders. Flutes on each of the end mills' cutting heads carry chips away from the workpiece to prevent damage to the end mill or workpiece. Square end mills are used on CNC or manual milling machines.
End Mill Flutes - What Are They, and How Many Do I need?
The Spiral-shaped cutting edges on the side of the end mill are called flutes.
Flutes provide an empty path for the cutting chips to escape from when the end mill is rotating in a workpiece.
End Mills have either 2, 3 or 4 flutes per bit. 2 and 4 flutes are the most popular.
2 Flute End Mills (Slot drills):
- For use on wood and aluminium.
- Fewer flutes are best for chip evacuation, keeping the bit cooler, but leaving a rougher surface cut.
- 2 flutes are best for use on Wood and aluminium as these produce very large chips in comparison to other materials.
- 2 flute end mills are also referred to as slot drills.
4 Flute End Mills:
- For use on most other materials.
- 4 flutes are used on most other materials, can cut harder materials than 2 flutes and will create an overall smoother surface finish.
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.