Kennametal Beyond Blast: How Coolant-Through Inserts Change Turning

Kennametal’s Beyond Blast technology represents a fundamentally different approach to coolant delivery in CNC turning. Rather than flooding the cutting zone from external nozzles, Beyond Blast channels high-pressure coolant directly through the insert itself, delivering the fluid precisely to the chip-insert interface where it has the greatest impact on chip breaking, temperature control, and tool life. This article examines the engineering behind Beyond Blast, quantifies its performance advantages, and identifies the applications where it delivers the strongest return on investment.

Beyond Blast Insert Design

Beyond Blast inserts feature an internal coolant passage that runs from the bottom of the insert through the carbide body to an outlet on the rake face, positioned immediately behind the cutting edge. The coolant exits through a precisely shaped nozzle orifice of approximately 0.8 to 1.2 mm diameter, creating a focused jet that impacts the chip at the point where it first contacts the rake face.

The insert geometry is built around Kennametal’s Beyond platform, which uses advanced PVD or CVD coatings on engineered substrates. The most common Beyond Blast grades include KCP25B for ISO P15-P30 steel turning, KCP35B for ISO P25-P40 heavy roughing, KCS10B for ISO S05-S20 heat-resistant alloys, and KCU25B for ISO M15-M30 stainless steel. Each grade is available with the internal coolant passage integrated into the standard ISO insert form factors including CNMG, WNMG, and DNMG shapes.

Coolant Delivery System Requirements

Beyond Blast requires a high-pressure coolant system delivering fluid at 70 to 350 bar (1000 to 5000 psi) through the toolholder to the insert. The toolholder must be specifically designed for Beyond Blast, with internal coolant channels that connect the machine’s coolant supply to the insert’s internal passage. Kennametal offers dedicated Beyond Blast holders in both square shank and Coromant Capto-compatible configurations.

The coolant flow rate through each insert is approximately 2 to 5 liters per minute depending on the orifice size and system pressure. At 200 bar, the jet velocity exiting the insert nozzle reaches approximately 200 meters per second, creating an impact force sufficient to break chips and create a hydrodynamic wedge between the chip and the rake face.

For machines without built-in high-pressure coolant systems, Kennametal recommends aftermarket pump units rated for a minimum of 100 bar to achieve meaningful Beyond Blast benefits. Below 70 bar, the coolant velocity is insufficient to penetrate the chip-insert interface, and the system behaves essentially as conventional flood cooling with the added complexity of internal routing.

Chip Breaking Performance

The most immediately visible benefit of Beyond Blast is improved chip control. The high-velocity coolant jet creates a hydraulic wedge that forces the chip to curl more tightly and break into shorter segments. In tests on 1045 steel at 250 m/min, 0.30 mm/rev feed, and 2.5 mm depth of cut, conventional flood cooling produced long, stringy chips averaging 300 to 500 mm in length. Beyond Blast at 200 bar produced chips averaging 20 to 50 mm, classified as favorable short helical chips under ISO 3685 chip classification standards.

This chip breaking improvement is particularly valuable when machining ductile materials such as low-carbon steels, aluminum alloys, and austenitic stainless steels, which naturally produce long, tangled chips that can wrap around the workpiece, damage surface finishes, and create safety hazards. In stainless steel 316 turning, Beyond Blast reduced the chip length from an average of 400 mm with flood cooling to approximately 30 mm at 150 bar pressure.

Tool Life Improvements

Beyond Blast extends insert tool life through two mechanisms: thermal control and reduced friction. The internal coolant delivery removes heat from the chip-insert interface more effectively than external flood coolant, which largely bounces off the chip surface without penetrating to the contact zone. Testing with KCP25B inserts on 4140 steel at 220 m/min, 0.25 mm/rev, and 2.5 mm depth of cut showed the following tool life results:

The data demonstrates that Beyond Blast provides a significant advantage over external high-pressure coolant delivery at equivalent pressure levels. The 45 percent improvement at 100 bar compared to external cooling at the same pressure is attributable to the precise coolant placement at the chip-insert interface, which external nozzles cannot achieve due to the physical obstruction of the chip curling over the rake face.

Surface Finish Benefits

Beyond Blast’s ability to control chip flow and reduce temperature at the cutting edge also improves surface finish. On 1045 steel finishing passes at 0.15 mm/rev feed and 0.5 mm depth of cut, Beyond Blast with KCP10B grade at 300 m/min produced Ra values of 0.4 to 0.6 micrometers, compared to Ra 0.8 to 1.2 micrometers with flood cooling under identical parameters. The improvement is attributed to the reduced built-up edge formation and more stable chip flow achieved with the internal coolant delivery.

Applications Where Beyond Blast Excels

The technology delivers the strongest return on investment in specific application categories. Aerospace turning of titanium and nickel-based alloys benefits enormously because these materials generate extreme temperatures at the cutting edge and produce difficult-to-break chips. In Ti-6Al-4V turning at 50 m/min and 0.15 mm/rev, Beyond Blast with KCS10B grade extended tool life from 8 minutes with flood coolant to 22 minutes at 200 bar, a 175 percent improvement.

Automotive high-volume production of steel components benefits from the combination of improved chip control and extended tool life. In a production trial turning 500,000 steering knuckles from 1045 steel, Beyond Blast reduced insert consumption by 35 percent and eliminated chip-related downtime events that had previously occurred approximately twice per shift.

Oil and gas machining of duplex stainless steels and corrosion-resistant alloys is another strong application, where the high-pressure coolant breaks the tough, work-hardened chips that are characteristic of these materials. On duplex 2205 stainless steel, Beyond Blast reduced chip wrapping incidents by over 90 percent compared to flood cooling.

Limitations and Considerations

Beyond Blast is not universally advantageous. The technology requires a significant investment in high-pressure coolant infrastructure if the machine tool does not already have it. The specialized inserts cost approximately 15 to 25 percent more than standard inserts of the same grade due to the internal passage manufacturing complexity. The dedicated toolholders are also more expensive and are not cross-compatible with standard inserts.

For light-duty operations on free-machining materials such as 12L14 steel or 6061 aluminum, the chip breaking and tool life benefits of Beyond Blast may not justify the additional system cost and complexity. These materials produce manageable chips under conventional cooling conditions and generate lower cutting temperatures that do not push the limits of standard flood coolant.

Comparison with Competitor Coolant-Through Systems

Beyond Blast is the only system that delivers coolant through the insert body itself. Competitor systems use external nozzles integrated into the toolholder, which provide directional coolant flow but cannot match the precision of the internal delivery. This gives Beyond Blast a measurable edge in chip breaking and tool life at pressures above 100 bar, though at a higher insert cost premium.

Conclusion

Kennametal Beyond Blast technology represents a significant step forward in coolant delivery for CNC turning. By routing high-pressure coolant through the insert to the exact point of chip formation, it achieves superior chip breaking, extended tool life, and improved surface finishes compared to both flood cooling and external high-pressure systems. The technology delivers the strongest ROI in aerospace, automotive, and oil and gas applications where difficult-to-machine materials and high production volumes justify the infrastructure investment and premium insert costs.