by Bernard Martin

Tool coatings play a critical role in optimizing performance, extending tool life, and reducing overall operating costs in most all cutting tool applications today. Rocky Mountain Blue™ nACo® Coating is a next-generation nanocomposite (NC) coating designed to push the boundaries of high-performance drilling and machining. Manufactured using a Platit-exclusive LARC (Lateral Rotating Cathode) coating process, this advanced multilayer coating system enhances wear resistance, thermal stability, and friction reduction.

Understanding Nanocomposite Coatings (nACo®)
The term nACo® refers to a nanocomposite coating structure, where ultra-hard nanocrystalline grains (such as TiN, TiAlN, or AlCrN) are embedded in an amorphous silicon nitride (SiN) matrix. This structure prevents grain growth and enhances hardness by creating a fine nanoscale grain distribution.

A useful analogy is wet sand versus dry sand—where dry sand shifts underfoot, but wet sand offers greater resistance due to the spaces between grains being filled with water. Similarly, the SiN matrix locks nanocrystals in place, increasing surface hardness and durability.

Key Features of Rocky Mountain Blue™ nACo® Coating

• Extreme Hardness: The nanocomposite structure significantly increases coating hardness, enhancing tool longevity and wear resistance.
• Superior Thermal Stability: Maintains structural integrity at temperatures up to 1200°C, making it ideal for high-speed and dry machining applications.
• Low Friction Coefficient: Reduces heat generation and tool wear, contributing to smoother and more efficient cutting performance.
• Proven Tool Life Enhancement: RMT (Rocky Mountain Twist) testing demonstrated a 40% increase in tool lifecompared to uncoated tools when dry drilling.
• Optimized for Steel and Stainless Steel: Delivers better performance than traditional TiAlN coatings, increasing feeds and speeds while maintaining or improving tool life.

Triple-Layer Multiphase Coating Architecture
Rocky Mountain Blue™ nACo® utilizes a triple-layer coating system, strategically engineered for enhanced adhesion, hardness, and thermal resistance:

1. TiN (Titanium Nitride) Base Layer
   • Improves adhesion to the substrate
   • Enhances wear resistance
2. TiAlN (Titanium Aluminum Nitride) Middle Layer
   • Provides high hardness
   • Reduces friction for extended tool life
3. TiAlN/SiN (Silicon Nitride) Top Layer
   • Acts as a temperature-resistant ceramic barrier
   • Promotes nano-scale structural reinforcement
   • Ensures stability in extreme heat conditions

These three layers work together to create a 10µm thick multilayer hard coating—one-fifth the thickness of a human hair (50µm), yet offering immense performance benefits.

Advantages Over Traditional Coatings
While TiAlN and AlTi(Si)N coatings are common in high-performance cutting tools, Rocky Mountain Blue™ nACo® Coating outperforms them in several critical areas:

With its ability to support higher speeds and feeds while maintaining a lower cost per hole, nACo® provides a substantial return on investment (ROI) for manufacturers seeking improved productivity.

Engineered for High-Speed Steel (HSS) and Cobalt (HSCO) Tools
While many nanocomposite coatings are reserved for carbide tooling, Rocky Mountain Blue™ delivers unprecedented performance enhancements on HSS and HSCO tools. This is a game-changer for industries relying on high-speed drilling operations in challenging materials like stainless steel and hardened steels.

Rocky Mountain Blue™ nACo® Coating represents a significant leap forward in cutting tool technology. With its nanocomposite structure, extreme thermal stability, low friction coefficient, and proven tool life extension, it sets a new benchmark for performance-driven machining applications.

By incorporating this next-generation coating, manufacturers can achieve increased productivity, lower tooling costs, and enhanced machining efficiency, making Rocky Mountain Blue™ a must-have solution for high-performance drilling and machining.

For more information contact F&L Technical Sales for expert guidance on how nACo® technology can optimize your machining processes.

written by ​Bernard Martin

Rocky Mountain Twist Drill's introduction of Blue nACo coating is a truly revolutionary surface treatment to enter the market in the drilling segment.

​Blue nACo was developed by PLATIT, an independent, family-owned company headquartered in Selzach, Switzerland.  PLATIT is a manufacturer of high-tech PVD and PECVD hard coating equipment for tools and machine components.

Blue nACo is an AlTiSi-based nanocomposite coating and performs best in the field of milling and drilling C-steels and outstanding performance in superalloys, hard material machining, and high heat applications. The use of nACo provides excellent adhesion and good performance even for more unusual applications such as milling with coated ceramic tools and CBN tools.

This treatment has been shown to improve drilling operations with its exceptional lubricity, unmatched hardness, and impressive heat resistance. An AITiSi-based nanocomposite coating,

The culmination of over 20 years field testing, Blue nACo coating has demonstrated an elevated the performance of Rocky Mountain Twist Drill's products. This coating is a testament to the commitment to pushing boundaries and delivering solutions that meet the evolving demands of the metalcutting sector.

What do you need in a drill coating particularly for superalloys, hard material machining, and high heat applications?  Typically the goal is a super thin coating layer that compliments the drill geometry and grind finish, a high hardness for wear resistance and a high level of lubricity so that the chips can slide up and out of the flutes.

Keep in mind also that there's a tremendous amount of heat generated in the cutting tool process so the coating needs to be able to not only withstand that heat but also be "slippery" e.g. have a low coefficient of friction, aka lubricity, to evacuate the chip quickly. Blue nACo coating has pushed the boundaries of that desired balance in each of those categories.

Lubricity, as measured by the coefficient of friction receives a significant boost with the Blue nACo coating. The incorporation of nanocomposite technology reduces adhesion between cutting edge of the and workpiece. This ensures reduced friction and enhanced wear resistance, resulting in smoother drilling operations. It translates to improved chip evacuation, reduced tool wear, and increased tool life – a trifecta that directly impacts productivity and cost-effectiveness.

As an indicator of the material's ability against deformation, hardness has been studied for more than a century. Adding a coatings provides an extra layer of protection to the drill, ensuring longevity and durability with this additional hard wearing layer.  

​The Nano-hardness of the Blue nACo coating is 39-41 GPa (which roughly converts to Micorhardness ~3977 ~ 4181Hv) which is in the higher hardness range when compared to many other common coatings used on drills. In  Rocky Mountain Twist Drill users can expect consistent performance even in the face of challenging materials, making the Blue (nACo) coating an invaluable asset for demanding drilling applications.

Heat resistance is a critical factor in drilling operations, where elevated temperatures can compromise tool integrity and precision. According to Platit, the maximum service temperature for the coating is 1200°C or about 2192°F. which is substantially higher that the most common coatings used on drills such at TiN, TiCN, TiAlN and AlTiN. 

The Blue nACo coating advanced thermal stability ensures that the drill maintains peak performance even in high-temperature environments, reducing the risk of premature tool failure and minimizing downtime.

Behind the scenes, Platit Coating Chambers has played a pivotal role in bringing the Blue (nACo) coating to fruition at Rocky Mountain Twist Drill. Operating around the clock, their state-of-the-art facilities have been dedicated to applying this surface treatment, to their very deep drilling product offering.

The Blue nACo coating represents a leap forward in drill surface treatment technology. Rocky Mountain Twist Drill's dedication to providing its customers with tools that embody precision, durability, and efficiency is exemplified in this cutting-edge coating. As the metalcutting industry continues to advance, the Blue nACo coating stands poised to make a lasting impact, setting a new bar for performance and reliability in drilling operations.