# cnc vs regular bits, right/left?



## Goblu (Mar 5, 2012)

I've been looking at spiral upcut bits. What I'm running into is finding bits described as for CNC. Here's an example
http://www.amazon.com/Yonico-31212-...3890&sr=1-1&keywords=yonico+up+cut+router+bit

I've used spiral upcuts and downcuts from Whiteside (5mm and 1/4" dia mostly) quite a bit, but some of these other bits seem to come in different diameters than those, which is why I was wondering how CNC bits would differ from what I've used. The ones that are 1/4" and 1/2" shanks. I know the cnc bits sometimes have different diameter shanks.

Also, sometimes they are described as being right or left turning. I'm assuming that is either upcut or downcut, but don't know if that's right.


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## Davif (Nov 24, 2014)

There isn't much difference in the bits other than the quality of the carbide. CNC bits should have a longer life. If you are getting a good cut and long life out of your other cutters, I wouldn't worry about it. 

I wouldn't run a down cutter in a CNC. You will load your cutter up and overheat it and the material. Run up cut cutter to clear the chips and if your machine can handle it, run with climb cutting.

Thanks,
David


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## Goblu (Mar 5, 2012)

Thanks, David. Whiteside does not have the range of sizes that are available for CNC bits from other mfgs. And less expensive from some of them. For the ones I use a lot, I'll stay with Whiteside, but will likely explore some others if I need a different size for something. And yonico looks like a good bet from what I've read here.


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## Cherryville Chuck (Sep 28, 2010)

Onsrud caters especially to the CNC markets, both metal and wood. They have a few profile wood bits but that's all. They have many sizes in imperial and metric, most with the same size shank but not all. They also offer different bit geometries for jobs like cutting plastics, aluminum, phenolic, and foam. You can find them by searching for Onsrudcutter2010.


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## Goblu (Mar 5, 2012)

I suspect I wasn't clear, but I don't have a cnc machine (alas!). I was just wondering if I could use ones that said cnc in a regular router. I had that question answered, and also found that the left twist is for cnc only, not for use in a regular router. 

But it is interesting about the Onsrud bits. Can you use them in a regular router if you want to cut plastic, metal, etc?


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## Cherryville Chuck (Sep 28, 2010)

Yes. They have bits with different geometry for plastics. You just have to pick one with 1/4 or 1/2 shank. I bought a bunch on eBay they were trying to get rid of. I have shank sizes in 1/4, 3/8, and 1/2 in Imperial. I have metric sized ones in 6, 8, 10, and 12mm. I bought bushings for the 3/8, 6, and 8mm. The 10 is supposed to fit 3/8 and I have buy a 12mm collet for one router but at the price I paid for the bits it's worth it. They still offer some bits on eBay at cheap prices under the seller name onsrudcutter2010.


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