Hi all,

I don't have any experience using single flute router bits of any kind and was wondering why you would use one instead of a two flute.

I see they come in various types like up, down and even compression.

When you have a fixed high RPM and a machine that is not stable enough to cut at a decent rate.

Another reason is for lighter machines that cannot cut as fast. The bits last longer at low cut speeds since the chip load works out to be closer to what is recommended.

-Also cutting plastics/acrylic & other similar products

A single flute bit is going to have more steel in the core of the bit. As such it will be stronger. I've used them on occasion when I was concerned about the potential for bit breakage.

BH Davis

we use it for plexiglass

Also used where quality of cut is not as important. We have a lot that use them to
cut out sinks and windows in doors where something will be covering it like a frame of some kind.

Thanks for the responses, would a single flute bit be good for small parts were the CNC can't accelerate to its programmed feed speed since it runs slower anyway

Jack, Yes kind of. the issue is the smaller diameters are hard to make in carbide tipped. Once you get so small, you can only run so much chip load without breaking the bit. They can be made in Solid Carbide, but they are fragile as well.

While in theory the single flute can handle the chip load of the smaller part at the slower speed the reality of small parts cutting is that you want as little pressure on the part as possible. A single flute bit will produce more side pressure on the part than a 2 flute bit. That is because on each rotation the 2 flute bit will take two small bites of wood while the single flute bit will take 1 larger bite.

BH Davis

Look @ the recommended feeds and speeds from one of the major manufacturers, Onsurd has good info on their site. There is always a tradeoff, if you want a particular # of cuts per inch for finish quality your feed rate will be slower for the single flute. That may produce less than an ideal chip load.