1/4″ Spiral Compression Chipbreaker (AstraHP Coated)

Spiral Compression CNC Router Bit that features 2 flutes with a cutting tip diameter of 1/4 inch and a 1 inch length of cut. Our compression bits are designed for CNC/Router applications requiring high feed rates and compression cuts. They work well for double-sided melamine or laminated material.

How Chipbreaker Bits Work:

Chipbreaker bits feature unique notch profiles, creating a serrated cutting edge, these notches break down chips into small, manageable pieces during the machining process. This type of geometry can boost your efficiency by minimizing machine downtime to clear large chips from the workpiece, improve bit life by minimizing the cutting force on the bit during machining, and allow for more accelerated speeds and feeds.

As a chipbreaker bit rotates and its cutting edge impacts the workpiece, material is sheared off from a part, creating chips. When that cutting process is interrupted, as is the case with chipbreakers in the cutting portion of the bit, chips become smaller in length and are easier to evacuate. Because the chipbreaker notches are offset flute-to-flute, a proper, flat surface finish is achieved as each flute cleans up any excess material left behind from previously passed flutes.

What is a Compression Bit?

A Compression bit is a spiral bit that combines up cut and down cut action into one bit. The cutting tip pulls the fibers and chips up towards the center of the workpiece. The rest of the bit is cutting and pushing wood fibers down, also towards the center of the workpiece. This up cut down cut action is what leaves a sharp, clean edge on both edges of your workpiece. The up cut flutes on a compression spiral bit is typically equal to the diameter of the bit, for example, a 1/2″ diameter has a up cut flute of 1/2″. The transition point is referred to as the ‘Spiral Change‘. We also offer several sizes of compression bit with a shorter up cut flute length which is referred to as a short flute compression (also called a mortise style compression bit). The slow-mo video clip below was shot by none other that Jonathan Katz-Moses and shows the cutting action of the compression bit. You can clearly see the difference between the up and down cut portions of the bit.

How do I use the Compression bit correctly?

In order to properly use a compression bit to get it’s full benefit, your initial cut needs to be slightly deeper than the upcut flute length, which as mentioned above is usually equal to the diameter of the bit. When used correctly, you shouldn’t see any tear out or chip out on the edges. In the video above, the bit on the left is seen cutting not deep enough to pass the up cut flutes. The bit on the right is set at the correct depth.

Can you use a Compression Bit in a router?

Yes, all of our compression and spiral bits can be used in a CNC, handheld router or a router table.