Insert DesignationsCarbide inserts use a coding system of
numbers and letters to describe their shape, dimensions, and
important parameters. For example, the designation of the insert
shown in Figures 11-16 is aCNMG-433.
Figure 17: Carbide Insert Designation
Shape (CNMG-433)There are at least 18 different shapes of
carbide inserts. The most commonly used are shown in Table 8.1 with
their letter designation. The angle in this designation refers to
the included nose angle at the cutting radius of the tool.Table
8.1: Common Insert Shape Codes
DesignationShape
TTriangle
SSquare
C80 degree diamond
D55 degree diamond
V35 degree diamond
RRound
Clearance Angle (CNMG-433)Clearance angle is the draft on the
face(s) of the insert that contact material during machining. More
about insert angles a little later.Table 8.2: Common Insert
Clearance Angles
DesignationClearance Angle
N0 Degrees (No Draft)
A3 Degrees
B5 Degrees
C7 Degrees
P11 Degrees
Tolerance (CNMG-433)This is how much variation is allowed in the
dimensional size of the insert. Tolerances described with this
parameter include the corner point (nose radius), thickness, and
I.C. Typical tolerances are shown in Table 8.3:Table 8.3: Typical
Insert Tolerances (Inch)
DesignationCornerpointThicknessI.C.
M.002-.005.005.002-.005
G.001.005.001
E.001.001.001
K.0005.001.002-.005
Hole/Chip Breaker (CNMG-433)The hole/chip breaker designation
describes both features with one letter. The hole in the insert and
tool holder must match. If no letter exists in this field, then the
insert does not have a hole to secure it to the holder, and is held
by clamp force only.Table 8.4: Common Insert Hole/Chip Breaker
Configurations
DesignationHole ShapeChipbreaker Type
GCylindricalSingle-sided
W40-60 deg, double c-sinkNone
RNoneSingle-sided
T40-60 deg, double c-sinkSingle-sided
PCylindricalHi-double positive
ZCylindricalHi-double positive
I.C. Size (CNMG-433)Inserts are measured by the diameter of an
inscribed circle. I.C.'s range from .0625 in to 1.25 in. Table 8.5
lists the sizes you are most likely to use.Table 8.5: Common
Inscribed Circle Sizes
DesignationDecimal (inch)Fractional (inch)
3.3753/8
4.5001/2
Thickness (CNMG-433)Insert thickness.Table 8.6: Common Insert
Thickness
DesignationDecimal (inch)Fractional (inch)
3.1873/16
4.2501/4
Nose Radius (CNMG-433)Insert cutting nose radius.Table 8.7:
Common Cutting Nose Radius
DesignationDecimal (inch)Fractional (inch)
1.0161/64
2.0311/32
3.0473/64
The insert shapes, sizes, and designations in these tables are
just of few of what is available. Any lathe tool catalog or
manufacturers web site will show many more.It is not important to
memorize every tool shape or designation scheme. It is important to
know insert terms and specifications to understand insert
recommendations from the tool representative or technical resource
to select the correct insert for the application.
MCLN R/L for Negative 80 CNM_ Inserts
MCMN N for Negative 80 CNM_ Inserts
MCRN R/L for Negative 80 CNM_ Inserts
MCKN R/L for Negative 55 DNM_ Inserts
MDJN R/L for Negative 55 DNM_ Inserts
MDPN N for Negative 55 DNM_ Inserts
MRGN R/L for Negative RNM_ Inserts
MSDN N for Negative SNM_ Inserts
MSKN R/L for Negative SNM_ Inserts
MSRN R/L for Negative SNM_ Inserts
MSSN R/L for Negative SNM_ Inserts
MTEN N for Negative 60 TNM_ Inserts
MTFN R/L for Negative 60 TNM_ Inserts
MTGN R/L for Negative 60 TNM_ Inserts
MTJN R/L for Negative 60 TNM_ Inserts
MVJN R/L for Negative 35 VNM_ Inserts
MVVN N for Negative 35 VNM_ Inserts
MWLN R/L for Negative 80 WNM_ Inserts
SCLC R/L for Positive 80 CCMT Inserts
SCMC N for Positive 80 CCMT Inserts
SDJC R/L for Positive 55 DCMT Inserts
SDPC N for Positive 55 DCMT Inserts
SSDC N for Positive SCMT Inserts
STEC N for Positive 60 TCxx Inserts
STFC R/L for Positive 60 TCxx Inserts
STGC R/L for Positive 60 TCxx Inserts
STJC R/L for Positive 60 TCxx Inserts
SVJC R/L for Positive 35 VCxx Inserts
Mini Toolholder and Boring Bar Set