Educate me please

[Monty]

After reading and researching jcm71's post about carbide cutters, will someone please tell me what the R### refers to in the description of the cutter?

 

[jcm71]

R100 = 4 inches approximately.

 

[jttheclockman]

After reading and researching jcm71's post about carbide cutters, will someone please tell me what the R### refers to in the description of the cutter?

OK class settle down. Here you go: edges : radius(or round)100mm

 

[leehljp]

And for those who don't understand this - Radiused squares are basically "Square" inserts that have a radiused edge. Square edges on inserts require absolutely perfect cuttings and holding. It requires very good hand hold on the tool, perfect eye-hand coordination, OR the square's corners (right-left side) will leave a number of tiny gouges where hand held alignment is not absolute perfect. THEREFORE the "radiused" squares were invented to eliminate the many imperfections left on the pen due to imperfect holding of the tool.

A radiused square is a square with a tiny bit of radius on it. R100, as mentioned - is that the edges have a radius of 100mm or about 4 inches, or equal to a circle (diameter) of about 8 inches or 200mm. That is not square but close enough that it prevents the edges digging in.

NOW For another question along this line for you expert insert users: Is there a true "square" insert with rounded "corners", say 1/32" or there about - that prevent the edges digging in?

 

[Monty]

So then it is being redundant when it states R100 4 inches? And R105 would be essentially the same?

 

[jttheclockman]

So then it is being redundant when it states R100 4 inches? And R105 would be essentially the same?

Yes but that is usually a Horn cutter Brand name..

Carbide cutters as we use them in the wood turning field are basically all scrappers. Some people have the ability to get them up on the edges and use as a shearing cutter. Not easy to do but can be done.

Now you have to remember a few things. No to Hanks question about rounded edges on a square cutter unless special made for wood turning. Yes they have for metal cutting and a whole lot more shapes than for wood.

You have to talk carbide cutter inserts because the same letter and number system can be found in other cutting tools such a router bits or milling bits. Same goes for metal cutting inserts.

Now as far as are these any good. I would have to say for the price the carbide used is of a lesser grade. There are different grades of carbide in all cutting tools including tablesaw blades, bandsaw blades and so forth. Are these good quality. I never used them and for the prices I would not hesitate to try them. They claim there is no middleman so that helps pricing. You can buy others on Ebay for as cheap but again do not know quality.

 

[keithlong]

I use the square radius 15x15 mm and usually buy them from global tooling supply for 3.50 each and they work good on wood and acrylic and deer antler. I can hold the tool at an angle and using the radius center of the insert get a smooth cut on wood and acrylic. It is tricky to learn to use it that way, but the results are well worth the time.

 

[Monty]

Thanks everyone for the replies. I just wasn't sure what the R### stood for.