CCMT 32.51

[TWS]

Hello,
some of my tool holders came with CCMT 32.51 inserts. I am looking to buy some new inserts from a quality company and my toolholder company says any 300 series will fit.
I do not understand the carbide insert numbering system, first off looking for 300 series is confusing and second what is the difference between 32.51 and 32.52?
What exactly does 300 series mean? I found 304, 321 and others but want to insure i purchase the correct fitting inserts as the price for Sandvik, Kenametal, Mistubishi is not cheap.
Any insight would be greatly appreciated

 

[Mitch Alsup]

First thing you need to understand is that there is a metric and an English-unit sized inserts that are interchangeable.

The first number is the size of the insert which needs to be matched to your tool holder.

The other thing I remember is that the last digit (of 4) is the tip radius 0 being point sharp, higher numbers have increasingly large tip radii. So, you might use a 32.53 insert for roughing (large metal removal) and use a 32.51 for finish passes.

You will find inserts for softer metals {aluminum, copper, brass,...} inserts for mild steels, and inserts for harder ferrous metals. And when the metal gets really hard, you switch over to CBN inserts. There are also various chip breakers available with the various hardness's of the carbide in the insert.

 

[davidpbest]

"300 series" is a pretty vague specification - makes me question the quality of the toolholder you have. My assumption would be that it means any CCMT insert with an I.C. (inscribed circle) of 3/8". So a designation of 32.5X is indicating the I.C. is 3/8" with a thickness of 5/32". The last digit is the nose radius:



So CCMT32.51 has a nose radius of 1/64 and would be suitable for finishing work. A CCMT32.52 has a more robust nose and better choice for roughing. If you're using this on a lathe, your depth of cut should be AT LEAST one-half the nose radius.

 

[S5rx7]

There is also a color chart to help distinguish what cuts what better. Here's a few links to help you understand.

Insert Designation Chart - provides ANSI and ISO designation code definitions for carbide insert shapes, relief angles, tolerances, chipbreaker codes, hole types, size values, thickness values, radius values, wiper lead angle, wiper clearance angle,

Carbide Insert Designation Chart

www.carbidedepot.com

Carbide Insert Grade Range Chart - provides ISO and ANSI code definitions for grade application ranges of carbide inserts for P steel applications, M stainless steel applications, K cast iron applications, and C scale values

Carbide Insert Grade Range Chart

www.carbidedepot.com

Sandvik Coromant

www.sandvik.coromant.com

After analyzing the links here you can see sandvik offerings

Sandvik Coromant

www.sandvik.coromant.com

Example: click on the first link. Take note of how the bit chip break design looks. Then scroll to the bottom and zoom in to see the bit dimensions.