Carbide Insert Designation/Identification

So you have a blue, green, yellow, clear box sitting on your desk, that one of the guys in the shop dropped off and said I need some more of these. Simple enough you think, I'll just order right off the box, problem is the box is smudged, and all you know is that it is and 80 degree carbide insert something or other.

Not that this ever happens. However, if you find yourself in this situation down the road, a good place to start is the ANSI designation chart for carbide inserts. This handy chart tells you whether that carbide insert is an 80 degree diamond, 55 degree diamond, or other. The insert thickness, insert tolerance, radius, clearance, hole type, and whatever other conditions may be listed at the end.

An example of a part # would look something like this: CNMA-432T DR-50


From looking at the insert designation chart, it tells me that this insert is:

1. 80 Degree diamond
2. Clearance of 0 degrees
3. Tolerance of =/-.002 to .005
4. Has a hole in it
5. Size is 1/2"- Number of 1/8ths of an inch in I.C. when I.C. is 1/4 inch and over
6. Thickness is 3/16" -Number of 1/16ths of an inch in thickness for I.C. of 1/4 inch and over
7. Has a corner radius of 1/32"
8. Has a chamfer cutting edge or K-Land


Now I know that is a lot of detail, but you get my drift. Use the sheet as a quick reference for turning tools and before you know it, it will no longer be necessary.

Thanks for reading.

-B