Kunshan Meiyaxing Hardware Machinery Co., Ltd. is a service-oriented enterprise specializing in the sales and operation of CNC cutting tools. We provide tungsten carbide milling cutters, milling inserts, turning inserts, grooving and parting inserts, drilling and boring inserts, multi-functional inserts, threading inserts, and other indexable inserts, along with matching tool holders and cutter heads. We have established long-term and stable strategic partnerships with well-known professional manufacturers of high-efficiency tungsten carbide milling cutters. The company possesses advanced production equipment from Swiss Rollomatic, German Walter, and Japanese Makino Seiki, as well as German Zoller-Genius 3S and American PG... With 1000 and other testing equipment, relying on our service and operations, and guided by strong R&D and production, we solve various tooling problems for processing and manufacturing enterprises. We aim to become a professional partner integrating "total tooling solutions and cost optimization services," with the goal of optimizing product processing costs, thereby achieving a mutually beneficial and common development.
In machining, the selection of milling inserts directly affects machining efficiency, workpiece quality, and tooling costs. Many operators have experienced this dilemma: the same milling cutter produces smooth machining on machine tool A, but frequently chips on machine tool B. The key issue is often not whether the tool itself is "good" or not, but whether the matching logic between the insert and the specific machining scenario is truly understood. This article systematically outlines the key points for selecting general-purpose milling inserts from four dimensions: insert material, coating technology, geometric parameters, and machining scenario matching.
I. Starting with Insert Material – Choosing the Right "Base" is Fundamental
The base material of the insert determines its basic profile of hardness, toughness, and heat resistance, and is the first step in selection.
1.1 High-Speed Steel (HSS)
High-speed steel inserts have moderate hardness (HRC) High-speed steel inserts (HSC) have a hardness of HRA 89-93 and a heat resistance of 800-1000℃, performing well at cutting speeds of 100-300 m/min. They exhibit good toughness and can withstand significant impact loads, but have poor heat resistance (≤600℃), making them suitable for low-speed cutting. On conventional milling machines with cutting speeds of 15-80 m/min, high-speed steel inserts offer excellent cost-effectiveness, particularly suitable for machining common materials such as carbon steel and alloy steel, especially economical when the workpiece hardness is below HRC 35. High-speed steel inserts are also a common choice in toughness-priority strategies for intermittent cutting in continuous cutting conditions.
1.2 Carbide Carbide is currently the most widely used insert material in general milling. Its hardness can reach HRA 89-93, and its heat resistance can reach 800-1000℃, performing exceptionally well at cutting speeds of 100-300 m/min. Common grades include YT15 (machining steel) and YW1 (general purpose). The cobalt content of carbide is typically controlled between 6% and 12%, and the tungsten carbide particle size is 0.5-2 μm. This combination ensures that the insert has both sufficient hardness and reasonable toughness.
1.3 Cermet Inserts
Cermet inserts combine the high hardness of ceramics with the toughness of cemented carbide, making them suitable for finishing. In steel milling, cermet inserts are preferred for finishing, as their surface finish is superior to that of ordinary cemented carbide. However, cermets have lower bending strength and fracture toughness than cemented carbide, making them unsuitable for heavy-duty roughing and interrupted cutting scenarios.
1.4 Ceramics and CBN
Ceramic inserts (Al₂O₃-based or Si₃N₄-based) have excellent hardness and high-temperature performance, making them suitable for high-speed cutting of cast iron and hardened steel. However, their toughness is relatively low, and their impact resistance is weak, requiring caution in interrupted cutting. For hardened steel (HRC 45~65), CBN (cubic boron nitride) inserts are the first choice; CBN tools have extremely high hardness (HV 2800~3500), good heat resistance, and are suitable for high-speed finishing and "turning instead of grinding" processes.
1.5 Diamond (PCD)
PCD (polycrystalline diamond) tools are currently the hardest insert material (HV 2800~3500). PCD inserts (with a silicon content of ≥13%) react with iron and are therefore unsuitable for machining steel materials. However, they are the preferred choice for high-speed milling of aluminum and copper alloys, achieving linear speeds exceeding 3000 m/min. For machining high-silicon aluminum (silicon content ≥13%), PCD inserts are the only option due to their exceptional wear resistance.
II. Coating Technology – The "Invisible Armor" of Inserts
Coating technology effectively improves the service life of cutting tools, giving them excellent overall mechanical properties, thereby significantly improving machining efficiency.
2.1 Two Major Coating Processes
· CVD (Chemical Vapor Deposition): Primarily used for coating cemented carbide inserts. The coating temperature is relatively high, suitable for medium- and heavy-duty high-speed machining. The process cost is low, making it suitable for mass production. A common CVD coating structure is a TiN-Al₂O₃-TiCN multilayer composite.
· PVD (Physical Vapor Deposition) : Suitable for solid carbide and high-speed steel tools. The coating temperature is low (below the substrate tempering temperature), and it will not affect the tool hardness and dimensional accuracy, making it suitable for applications requiring high precision.
2.2 Common Coating Types and Applications
Coating Color Characteristics Recommended Applications
TiN (Titanium Nitride) Gold Low coefficient of friction, good anti-adhesion, strong resistance to crater wear General steel machining, materials prone to tool adhesion
TiCN (Titanium Carbonitride) Gray High hardness, low internal stress, good toughness High-speed machining of steel, cast iron
TiAlN (Titanium Aluminum Nitride) Purple Good chemical stability, high hot hardness, oxidation resistance, suitable for dry cutting Stainless steel, high-temperature alloys, hardened steel
AlCrN (Chromium Aluminum Nitride) Gray High temperature resistance, wear resistance Difficult-to-machine materials, dry cutting
Al₂O₃ (Aluminum Oxide) Gray Excellent thermal insulation, high chemical stability High-Speed Cutting of Cast Iron and Steel
TiN coating is one of the most common coatings currently available, suitable for cutting steel and materials prone to tool sticking, resulting in a lower surface roughness and longer tool life. Compared to TiN or TiCN, TiAlN coating has higher thermal stability, thus gaining widespread application in high-speed cutting. Modern high-end inserts often employ multi-layer composite coating technology. For example, the Walter Tiger·tec® Gold series uses a structure of "outer gold ZrN surface layer + multiple Al₂O₃ intermediate layers + TiAlN base layer," balancing wear resistance, high-temperature resistance, and wear visibility.
2.3 The Influence of Coating on Cutting Parameters
Coating technology can effectively improve tool life by 30%~150%, while allowing for higher cutting parameter settings. For example, when machining 45 steel with a PVD TiAlN coated carbide insert, the cutting speed can be increased from the conventional 120 m/min to over 180 m/min.
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Contact us:Company name:Kunshan Meiyaxing Hardware Machinery Co., Ltd;Tel:8618962438699;Address: Room 3003, Building 3, Zhengtailong, No. 1288 Chengbei Middle Road, Kunshan City, Jiangsu Province, China;Email:myxcuttingtools@gmail.com;Website: https://www.myxcuttingtools.com
