Carbide Inserts

Carbide inserts are used for removing material. They are put into a holder and used on a lathe. The lathe is set to a specific depth and can only remove a specific amount of material per pass. As the material spins, the lathe cuts deeper with every pass. This is a great tool for all metal working people. It has a wide range of applications. You can reshape a surface removing as much or as little material needed. If you have an item with rough edges, you would use a bur to remove those edges.

You can find out about our products including solid carbide threading inserts, carbide cut off inserts, cobalt jobber drills, high speed tools, and corner radius cobalt end mills by browsing our catalog.

Let’s dissect the part number to better understand the carbide insert. For a complete list of character equivalents, see below:

Ex: CNMP431C5

"C" = Shape
"N" = Clearance
"M" = Tolerances, Cutting Point and Thickness
"P" = Hole and Face Type (for inserts without a hole, this letter code will not be present)
"4" = Size (i.c.)
"3" = Thickness
"1" = Radius or Chamfer
"C5" = Grade of Carbide

1st place: Shape

A 85 Degree Parallelogram
B 82 Degree Parallelogram
C 80 Degree Diamond
D 80 Degree Diamond
H Hexagon
K 55 Degree Parallelogram
L Rectangle
M 86 Degree Diamond
O Octagon
P Pentagon
R Round
S Square
T Triangle
V 35 Degree Diamond

2nd place: Clearance

N 0 Degree
A 3 Degree
B 5 Degree
C 7 Degree
P 11 Degree
D 5 Degree
E 20 Degree
F 25 Degree
G 30 Degree

3rd place: Tolerance

Cutting

A+/-.0002
B+/- .0002
C+/- .0005
D+/- .0005
E+/- .001
G+/- .001
M+/- .002 to +/- .005
U+/- .005 to +/- .012
RBlank with Grid Stock, all surfaces
SBlank with Grind Stock, top & Bottom only

PointThickness

=/- .001
+/-.005
+/-.001
+/-.005
+/- .001
+/- .005
+/- .005
+/- .005

4th place: Hole & Face Type

A w/ hole
B w/ hole
C w/ hole &2 C'Sinks
D Smaller than 1/4" ic w/ hole
E Smaller than 1/4" ic w/ hole
F Chip grooves on face, no hole
G Chip groves on face w/ holes
H Chip grooves on 1 face w/ hole
J Chip grooves 2 sides w/ hole & C' sink
M Chip grooves on 1 face w/ hole
P 10 Degree pos chipbreaker 2faces w/ hole
S 20 Degree pos chipbreaker1 side w/ hole

5th place: Size (Inscribable circle)

Put this digit over 8 to determine the size. I.e. our example number CNMP431C5 the 4 would go over 8 which equals 1/2" which is the inscribable circle.

6th place:Thickness

Put this digit over 16 to determine the size. I.e. our example number CNMP431C5 the 3 would go over 8 which equals 3/8" which is the thickness.

7th place: Radius or Chamfer

Put this digit over 64 to determine the size. I.e. our example number CNMP431C5 the 1 would go over 64 which equals 1/64" which is the radius. The exceptions are "0" which equals sharp corners, and "A" 45 degree chamfer. See below.

0 Sharp Corners
1 1/64" Radius
2 1/32" Radius
3 3/64" Radius
4 1/16" Radius
4 3/32" Radius
4 1/8" Radius
A 45 Degree Chamfer