Identifying Bits: Single or Doble Flute?

I am a bit confused about the bits I received. I ordered the following…

(1) ¼ Inch 2 Flute Up-spiral Bit
(2) ¼ Inch Single Flute Up-spiral Bit

My confusion is in identifying them, both the bits seem to have 2 flutes.

This diagram is how understand identifying bits.

Are both bits double flute or am I confused on how to identify them?

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Flutes are the side grooves just count them. Looks like both are double but hard to tell from the top

the one on the left looks like a compression bit, with its flutes crossing like that, but the angle makes it difficult
Neither of them look like the single flute bit that i got.

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If I count the flutes, then both are double. @Jatt you are correct, the one on the left has two flutes which wrap ccw but also has two short flutes at top which wrap cw. Is it a compression bit? If so what the benefits of a compression bit?


My understanding is compression bits reduce tear out on both sides of the board when you are doing through cuts / profile cuts. so on the top side of the board they are a down spiral and on the bottom side of the board they are an up spiral causing a cleaner shear of the material. The cut material hopefully clears out of the cut behind the bit and gets sucked up the vacuum hose.
Hope this helps.

Here’s a nice primer on the different kinds of bits:

I’ve been using mostly compression bits, the ones that they sell on the maslow shop have a nice low needed depth and seem to work really well with the maslow for cutting plywood and leaving clean edges on both the top and bottom of the cut.

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Going to follow this discussion :slight_smile:
Do you cut through 18mm at once? Which rpm and feedrate?

Try this:

Thank you

It looks like we sent you a compression bit instead of the single flute bit you ordered! Sorry! If you shoot an email to we’ll send you a single flute bit right away!