Lizhou Carbide Turning Inserts Series | Cemented Carbide CNC Turning Solutions

The daily tasks carried out in the workshop, put simply, all hinge on a few cutting tools: The outer circle must be turned smoothly, the end faces must be turned flat, and threads and grooves must be machined flawlessly—all of which ultimately depend on the cutting blades.

Our starting point for developing this turning tool series is simple: to provide CNC lathe, center-lathe, and automatic lathe operators with a set of carbide tools that are easy to use, durable, and cost-effective. Turning tool insert Whether it's batch turning or small-batch production of multiple varieties, we can always reliably get the job done.

I. The few blades that the workshop really can't do without

When many customers come to consult us, their first question is often not about technical specifications—but rather: “Is this carbide turning insert easy to use? Is it durable enough for turning? Is it stable or unstable?”

This LIZHOU turning series is designed specifically for the kinds of operations typically performed daily on a lathe: external cylindrical turning, end-face turning, rough turning, semi-finishing turning, and finishing turning.

We also have a specialized series of blades for thread turning, as well as for cutting and grooving. However, in this article, I’d like to focus specifically on the turning inserts themselves—after all, they’re the “mainstay” that account for the largest volume of use on lathes.

II. With a full range of shapes, assign different blades according to the different parts. 

In actual production, parts come in a wide variety of shapes, so a single cutting tool cannot handle them all. Currently, Lizhou’s standard CNC turning insert geometries include:

Diamond-shaped carbide insert: Outer circle +  It’s a versatile, widely used model that’s suitable for most everyday turning operations.

Square carbide inserts: Featuring high tip strength, they are particularly well-suited for rough turning operations involving large amounts of stock material, intermittent cutting, and relatively large depths of cut.

Triangular carbide inserts: Each insert has multiple cutting edges, making them ideal for stable and continuous turning operations and helping to conserve tool life.

Peach-shaped turning inserts: Often used on center-lathe machines and automatic lathes for machining small parts; they offer smooth cutting action and precise dimensional control.

Peeling Blade Series: Specifically designed for external cylindrical peeling and surface finishing, ensuring that the "skin" is processed more evenly and aesthetically pleasing.

For us, the advantage is simple: 
On the same production line, different parts can each select a suitable shape from the Lizhou carbide insert series, yet the shank system remains unified, making tool changes easy and management straightforward.

3. Positive angles also have their place, and negative angles also have their place.

Many machinists are accustomed to saying: “Negative-rake inserts can handle heavy loads, while positive-rake inserts offer superior cutting performance.” 
Lizhou’s approach is: We offer both options and recommend them based on different scenarios.

Positive rake angle turning insert: 
Suitable for thin-walled parts, small-diameter components, and workpieces such as stainless steel that are prone to deformation and heat generation. The cutting action is light, and the forces involved are minimal, making it less likely for the parts to be distorted or deformed under pressure. Additionally, the machine tool produces quieter operation.

Negative rake cutting insert: 
The cutting edge is more robust and has excellent impact resistance, making it ideal for castings, forgings, and rough blanks with substantial material allowances. It’s particularly reliable during intermittent turning operations and is the type many customers specifically request for rough turning applications.

The benefit of doing this is that you can select the appropriate combination of positive and negative rake angles based on the machine tool’s rigidity, clamping method, and workpiece type—rather than consistently relying on just one type, which can both damage the cutting insert and waste the machine tool’s performance.

4. Match the material to the corresponding grade and groove type—fewer chipping, more efficient work.

What really determines whether a cemented carbide turning insert is good or not is whether its grade and groove geometry are appropriately matched to the specific application. 
Lizhou doesn't go "out into the world" with just one grade of material; instead, it segments its products based on the material itself.

Cast iron turning (gray iron, ductile iron): 
Use a wear-resistant grade. +  Stable chip-breaking groove design, ideal for long-term high-speed external cylindrical and end-face turning; blade wear is even, resulting in excellent tool life.

Turning of steel parts (plain carbon steel, alloy steel): 
For rough turning, use blades with strong cutting edges and ample chip-breaking spaces; for semi-finishing and finishing turns, employ finer flute geometries that allow for both efficient cutting and precise control of dimensions and surface finish.

Stainless steel turning: 
The groove-type rake angle is larger, and the cutting edge is treated more sharply, reducing the formation of built-up edges and tool sticking. The blade is less likely to overheat and turn red, and the workpiece surface won't turn black.

High-hardness steel (quenched parts, die steel): 
Choose grades with higher chipping resistance, combined with appropriate cutting depth and feed rates, to ensure that the cutting edge maintains a stable tool life even under high hardness—rather than “breaking down after just a few cuts.”

Difficult-to-machine materials such as copper, aluminum, titanium alloys, and high-temperature alloys: 
The corresponding light-cutting groove geometry and high-temperature-resistant grades are designed to minimize surface tearing and effectively control burrs, making them ideal for parts with high precision requirements.

From the customer's perspective, it means doing everything possible to help you:

Use the corresponding carbide insert grade and groove geometry for different materials. 
The blade has few chipped edges, performs well under heavy use, and its lifespan is easy to predict.

V. High-quality tungsten steel +  The coating's lifespan must be clearly calculable.

What many customers care about is not how much a single blade can cut, but rather how consistently a box of blades can perform. 
To this end, Lizhou has devoted considerable effort to both the foundational materials and the manufacturing processes:

All use high-quality tungsten carbide cemented carbide substrates, and we personally control the pressing, sintering, and precision grinding processes—our goal is to ensure maximum consistency from batch to batch of turning inserts.

Depending on different working conditions—such as steel parts, cast iron, stainless steel, and difficult-to-machine materials—different routing options can be matched. PVD / CVD Some coatings focus primarily on wear resistance, while others emphasize toughness and chipping resistance.

Six: Let the lathe do more work, and let the cutting tools cause fewer problems.

In a nutshell: 
The strength of Lizhou carbide inserts lies not in how beautifully they’re described, but in how well they perform in your workshop.

Many shapes available to accommodate different parts and machine tools;

Both positive and negative angles are available, allowing you to select according to operating conditions.

For the material grade and groove type, minimize chipping on the blade.

A high-quality tungsten steel matrix combined with a stable coating ensures predictable service life.

Plus, with the matching of threading, cutoff, and grooving tools, you can equip the entire turning line with all the necessary cutting tools in one go.

If you’re currently using CNC turning inserts from another manufacturer and would like to explore more stable and durable alternatives, feel free to share with us your current material, typical parameters, and insert model number. Then, compare them with LiZhou’s corresponding turning inserts—just give them a real-world test. Your machine tool and workpiece will provide the answer.