WHY SPIRAL ROUTER BITS?

Standard 2 flute straight router bits contact your workpiece two times per revolution. This causes excessive vibration and potentially lots of tearout, even losing large chunks when transitioning from edge grain to end grain. Spiral flush trim router bits are designed to shear the wood and are constantly in contact with your workpiece all 360 degrees of revolution, causing no vibration and smoother cuts. This cutting action leaves a smooth surface without any vertical ridges. 

WHAT IS FLUTE DIRECTION?

Bits & Bits *Astra Coated* Spiral flush trim bits are available in three flute directions; up-cut, down-cut and compression. Direction is always in relation to the router; an up-cut spiral is pulling chips up towards the router. Down-cut spirals push chips down and away from the router. A compression bit is the best of both bits, with up-cut flutes at the tip next to the bearings and the down-cut flutes closest to the router. This effectively pulls the wood fibers towards the center of the wood being trimmed and reduces tearout or ‘fuzz’ along the top and bottom edge of your workpiece. Keep in mind when the router is upside down in a router table, the directions will reverse with a down-cut pushing chips up away from the router.

WHAT BIT SHOULD I USE?

If you are using a handheld router, any of the three bits will work well. If you are cutting through the wood and the bit will be ‘enveloped’ by three sides in wood, use a single direction (up-cut or down-cut). If you are first rough cutting your workpiece with a bandsaw or jigsaw and then trimming to the template, a compression works very well. If cutting with a template, we recommend a down-cut as the template will support the workpiece and produce very little tear out on the bottom edge. 

HOW DO I USE A FLUSH TRIM ROUTER BIT?

All of our spiral bits are designed to be used at between 16,000 and 18,000 RPM, which on most variable speed routers is at about middle of the dial. Running faster than 18,000 RPM can cause the bit to heat up and lose it’s sharp edge much quicker and can cause you to lose control of the router. We do not recommend using spirals in single speed routers.

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WHAT IS ASTRA COATING?

Astra Coating is our proprietary nano coating that we apply to our CNC bits, Whiteside router bits and our end mills. Formulated to lower heat built up by friction and abrasion as the tool is cutting, Astra Coating can extend the life of the bit 2-3x while allowing for faster feed rates.

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