What Is A Compression Bit?

CREDIT: excerpts from original article by Bits & Bits

What is a Compression Bit?

A compression bit is a unique spiral bit that integrates both up cut and down cut actions into a single design. The cutting tip is engineered to pull wood fibers and chips upward toward the center of the workpiece, while the rest of the bit simultaneously cuts and pushes the fibers downward, also directing them toward the center. This combined up cut and down cut action results in a sharp, clean edge on both sides of your workpiece. The up cut flutes on a compression spiral bit are generally equal to the diameter of the bit; for example, a 1/2" diameter bit will have a 1/2" up cut flute. The point where this transition occurs is known as the 'Spiral Change.' Additionally, we offer several sizes of compression bits with shorter up cut flute lengths, which are referred to as short flute compression or mortise style compression bits. The slow-motion video clip below, captured by Jonathan Katz-Moses, demonstrates the cutting action of the compression bit, clearly highlighting the differences between the up cut and down cut sections of the bit.

How do I use the Compression bit correctly?

For optimal use of a compression bit, it's essential that your initial cut is a bit deeper than the length of the upcut flutes, which generally matches the diameter of the bit. When executed properly, this method should eliminate any tear out or chipping on the edges. In the video provided, the bit on the left is cutting at a depth that is too shallow, whereas the bit on the right is set to the correct depth.

Can you use a Compression Bit in a router?

Yes, all Bits & Bits Brand and AstraHP compression and spiral bits can be used in a CNC, handheld router or a router table.

Bits & Bits brand bits, along with their AstraHP compression bits, are meticulously engineered for a variety of applications that require high feed rates and precise compression cuts. These tools are particularly effective for processing double-sided melamine or laminated materials, ensuring optimal performance and quality.