TNMG turning inserts are one of the most widely used 60-degree negative rhombic inserts in CNC machining. Known for their strong cutting edge, stable performance, and cost efficiency, TNMG carbide inserts are commonly applied in steel, stainless steel, cast iron, and high-temperature alloy machining.
In this article, we will cover the complete TNMG insert range, including TNMG1604, TNMG331, TNMG332, TNMG432, insert grades, chipbreaker types, material options (carbide, cermet, ceramic, CBN), holders, specifications, and how to choose the right TNMG insert for your application.
1. What Are TNMG Turning Inserts?
TNMG turning inserts are triangular negative inserts with six cutting edges (three per side).
They belong to ISO turning insert geometry, commonly used for medium to rough machining.
Key advantages:
Six cutting edges → excellent cost performance
Strong and stable cutting edge
Suitable for medium-to-heavy cutting
Available in carbide, ceramic, cermet, and CBN
Wide range of chipbreaker options
These features make TNMG inserts popular in general turning, facing, and profiling.
2. TNMG Insert Size & Common Models (TNMG1604 / 331 / 332 / 432)
Below are the standard TNMG insert sizes commonly used in global CNC machining.
Table 1: Common TNMG Insert Models & Dimensions
| Insert Model | ANSI Code | ISO Size | Cutting Length (mm) | Thickness (mm) | Hole Size (mm) | Corner Radius (mm) |
|---|---|---|---|---|---|---|
| TNMG1604 | TNMG 332 | 16 mm | 9.7 | 4.76 | 3.81 | 0.4 / 0.8 / 1.2 |
| TNMG331 | TNMG 160404 | 16 mm | 9.7 | 4.76 | 3.81 | 0.4 |
| TNMG332 | TNMG 160408 | 16 mm | 9.7 | 4.76 | 3.81 | 0.8 |
| TNMG432 | TNMG 220408 | 22 mm | 12.7 | 4.76 | 5.56 | 0.8 |
These codes appear frequently in Google searches and SEMrush keyword trends, making them essential SEO keywords for TNMG insert marketing.
3. Carbide TNMG Insert Range
Carbide remains the most widely used material for TNMG inserts due to its hardness, thermal resistance, and long tool life.
Carbide TNMG insert options include:
P-grade for steel (P10–P40)
M-grade for stainless steel (M10–M30)
K-grade for cast iron (K10–K30)
Coating types such as TiAlN, AlTiN, TiCN, CVD multi-layer coatings
For manufacturers in China (like Huana Tools), carbide TNMG inserts are the main product line due to the stability of performance and competitive pricing.
4. TNMG Insert Grades, Sizes, and Chipbreaker Types
Choosing the correct grade and chipbreaker directly affects tool life and surface finish.
Table 2: TNMG Insert Grades & Applications
| Grade Type | Material | Application | Features |
|---|---|---|---|
| P20–P30 | Steel | General turning | High wear resistance |
| P35–P45 | Steel | Heavy roughing | Strong edge toughness |
| M20–M30 | Stainless | Medium turning | Anti-built-up edge |
| K10–K20 | Cast iron | High-speed cutting | Good thermal shock resistance |
Chipbreaker Types for TNMG Inserts
MF / MM → Medium finishing
MK → For stainless steel
MR / MS → Medium cutting
MA / MP → General-purpose finishing
MR / R → Roughing
HF / HR → Heavy cutting
Different manufacturers may use different naming conventions, but the functions remain similar.
5. Ceramic, Cermet, and CBN TNMG Inserts
Beyond carbide, TNMG inserts are also available in specialized materials to support high-speed or high-hardness machining.
● Ceramic TNMG Inserts
Used for:
Cast iron
Heat-resistant alloys (Inconel / Hastelloy)
High-speed finishing
Features:
Extremely high temperature resistance
Fragile but ideal for ultra-high speed
● Cermet TNMG Inserts
Used for:
Stainless steel finishing
Low-carbon steel
Applications requiring high surface smoothness
Features:
Very smooth chip flow
Produces mirror-like finishes
● CBN TNMG Inserts
Used for:
Hard turning (HRC 50–65)
Hardened steels
Bearing steel / D2 / Cr12
Features:
Exceptional wear resistance
Replaces cylindrical grinding processes
6. TNMG Insert Holders and Toolholder Types
TNMG inserts use negative-rake tool holders such as:
MTGNR / MTGNL
DTGNR / DTGNL
PTGNR / PTGNL
STGNR / STGNL
WTGNR / WTGNL
These codes define:
Clamping method
Approach angle
Insert shape compatibility
A correct combination ensures maximum insert stability and chip control.
7. TNMG Insert Specifications (ISO/ANSI)
TNMG insert specifications follow ISO rules:
T = Triangle shape
N = 0° clearance angle
M = Tolerance class
G = Center hole (with chip groove)
Typical specification structure:
TNMG160404-MP-P25
Where:
16 = length
04 = thickness
04 = corner radius
MP = chipbreaker
P25 = grade
Understanding these codes helps machinists choose the precise insert for their material and cutting condition.
8. Competitive TNMG Insert Prices
TNMG inserts offer lower cost per cutting edge and longer overall life.
For many factories—especially in steel turning—TNMG is more cost-effective than CNMG or VNMG due to 6 cutting edges instead of 4.
Price varies by:
Material (carbide / CBN / ceramic)
Coating
Chipbreaker
Precision grinding
Brand vs. OEM
Chinese manufacturers provide extremely competitive TNMG insert prices while maintaining international standards.
9. Why Choose a Carbide TNMG Insert Manufacturer & Supplier in China?
China is the global hub for CNC inserts manufacturing.
Advantages include:
Full TNMG size range (1604, 331, 332, 432, etc.)
Custom chipbreaker development
Competitive OEM pricing
Fast delivery and large inventory
Coating options equal to mainstream brands
Manufacturers like Huana Tools offer stable quality + aggressive pricing, making them ideal partners for global distributors and factories.
10. How to Select the Right TNMG Insert for Your Application
| Material | Recommended Grade | Chipbreaker | Model | Notes |
|---|---|---|---|---|
| Steel | P20–P35 | MP / MS / MR | TNMG1604 / 332 | General turning |
| Stainless Steel | M20–M30 | MK / MS | TNMG331 | Avoid built-up edge |
| Cast Iron | K10–K20 | KR / KF | TNMG432 | High-speed dry cutting |
| Hardened Steel (HRC 50+) | CBN | N/A | TNMG1604 | Hard turning |
| Inconel / Alloy | Ceramic | SF / SM | TNMG332 | High-speed finishing |
Conclusion
TNMG turning inserts remain one of the most versatile and cost-efficient insert types in CNC turning. With a wide range of sizes—TNMG1604, TNMG331, TNMG332, TNMG432—materials such as carbide, ceramic, cermet, and CBN, and chipbreakers for every condition, they offer reliable performance across industries.
Whether you need high-speed machining, hard turning, stainless steel finishing, or cast iron productivity, the TNMG insert family provides a highly flexible solution.
