Onsrud 1/4" Cut Diameter Two Flute Compression End Mill for Wood and Laminated Wood

A combination upcut and downcut end mill cutter for best quality on the top and bottom edges of the material being cut. Very High Quality End Mill from Onsrud Will create a flat bottom surface

This is a tool from Onsrud that exhibits upcut and downcut flutes in the same cutting area of the tool. The upcut portion is on the end of the end mill, and the downcut portion is on the upper portion of the end mill. So, why would a cutting bit need this geometry of flutes? The upcut end mills leave a poor edge quality on the top of the work piece and conversely, the downcut end mills leave a poor edge quality on the bottom of the edge work piece. The reason for this is that the cutting action, either up or down, will respectively pull up the edges, or push down the edges. It's like pealing the skin off of the edge. If you have the cutting action in the opposite direction of the face of the edge (i.e. downcutting on the top edge), the skin of the wood is forced into the inner portion of the wood rather than the skin peeled up.

Cut Diameter - 1/4 inch or 6.35mm
Shank diameter - 1/4 inch or 6.35mm
Excellent Quality on Top and Bottom Edges of Cut

Soft Wood, Soft Plywood, Laminate Chipboard and Laminated Plywood:
Chip load: .015 to .017
Suggested Low End Feed Rate: 540 IPM
Suggested High End Feed Rate: 612 IPM

Hard Wood and Hard Plywood:
Chip Load: .014 to .016
Suggested Low End Feed Rate: 504 IPM
Suggested High End Feed Rate: 576 IPM

MDF (Medium Density Fiberboard):
Chip Load: .013 to .015
Suggested Low End Feed Rate: 468 IPM
Suggested High End Feed Rate: 540 IPM

All Feed Rates are based on 18,000 Spindle RPM