Two Flutes Compression End Mills - Carbide
1/8": Shaft 3.175mm, Flutes 22mm, Length 50mm
Ø4: Shaft 4mm; Flutes 25mm; Length 50mm
Ø6: Shaft 6mm; Flutes 32mm; Length 75mm
When working with any veneer finished material in your CNC machine, you will benefit from using a compression spiral end mill to make full depth cut. These bits are designed to leave clean edges on the top and bottom faces of any material. The compression bit's unique design pulls chips upward at the bottom of the stock and downward at the top face, producing chip-free surfaces that are perfect for cabinet and furniture parts. Compression cut spiral end mills are excellent for melamine, plywood, MDF and solid wood.
Typically there are two common types of end mill spiral geometry, up-cut and down-cut. An up-cut will give you a great finish on the bottom side of your workpiece when you cut all the way through the material as it is designed to pull chips upward causing a sheering action on the bottom. However, this causes a very poor finish on the top surface as the laminates of the plywood splinter along the cut line. Additionally, an up-cut end mill can cause delamination to the inner part of the material as well. Conversely, you can use a down-cut end mill which will give you a very nice finish on the top of the material but will often cause splinters on the bottom of the material.
The solution for the best finish quality on laminated material is to use a compression end mill. A compression end mill has a up-cut flute geometry from the tip to usually about 1/3 of the cutter length at which point it converts into a down-cut flute. The advantage is that the end mill, when used properly, will give you a nice clean top and bottom finish on your work piece.
In order to get the best finish using a compression bit, it is important that your first pass goes deep enough into your material so the down-cut spiral is engaging with the top surface of the material. This dimension is usually indicated by the manufacturer, however if it is not, you can always measure it with a pair of digital calipers. If you do not plunge the bit past the spiral change then it will act the same as an up-cut end mill and give you the same frayed finish.