Kennametal Beyond Blast: Coolant-Through Turning Technology
Kennametal’s Beyond Blast platform revolutionized CNC turning by integrating high-pressure coolant delivery directly through the cutting insert and toolholder. Unlike conventional external flood coolant, Beyond Blast delivers coolant at pressures up to 350 bar through precision-engineered channels in the insert itself, directing the fluid exactly where it is needed — at the chip-tool interface. This article examines the technology, available grades, and the performance gains that Beyond Blast delivers.
How Beyond Blast Works
Traditional coolant delivery relies on external nozzles that spray coolant toward the cutting zone. At high cutting speeds (above 200 m/min), the chip flow creates an air barrier that prevents coolant from reaching the actual contact area. Beyond Blast solves this by routing coolant through:
- Internal channels in the toolholder: Coolant enters through the tool shank and travels to the insert pocket
- Precision holes in the insert: The insert has laser-drilled or EDM-machined coolant passages (0.5-1.0 mm diameter) positioned on the rake face near the cutting edge
- Directed jet at the chip-tool interface: Coolant exits directly between the chip and the rake face, penetrating the contact zone that external coolant cannot reach
The result is a dramatic improvement in cooling efficiency, chip control, and tool life at any cutting speed.
Beyond Blast Insert Design
Beyond Blast inserts are available in standard ISO geometries — CNMG, WNMG, DNMG, and TPKN — with the addition of coolant-through holes. The inserts maintain full compatibility with standard tool pocket dimensions, requiring only the specialized Beyond Blast toolholder for coolant routing.
Key insert features:
- Coolant exit holes positioned 1.5-3.0 mm from the cutting edge
- Hole diameter of 0.8 mm for standard sizes, 0.5 mm for smaller inserts
- Reinforced hole edges to prevent stress concentration and cracking
- Available in all Beyond coating families
Available Beyond Blast Grades
| Grade | ISO Class | Coating | Speed Vc (m/min) | Best Application |
|---|---|---|---|---|
| KCP25B | P20-P35, M15-M30 | CVD Al2O3-TiCN (Beyond) | 150-320 | General steel turning with coolant-through |
| KCP35B | P25-P45, M25-M40 | CVD Al2O3-TiCN (Beyond) | 100-250 | Heavy roughing, interrupted steel |
| KCU25B | M15-M30, S15-S25 | PVD AlTiN (Beyond) | 80-220 | Stainless steel and superalloys |
| KCU10B | M05-M20, S05-S15 | PVD TiAlN (Beyond) | 120-300 | Finish stainless and HRSA |
| KCK20B | K10-K30 | CVD TiCN (Beyond) | 150-400 | Cast iron turning |
Performance Comparison: Beyond Blast vs Flood Coolant
Testing was conducted on AISI 4140 (280 HB) using CNMG 120408 inserts, KCP25B grade, at Vc=240 m/min, fn=0.3 mm/rev, ap=3.0 mm:
| Parameter | Beyond Blast (150 bar) | Flood Coolant (5 bar) | Dry Cutting |
|---|---|---|---|
| Tool life (min) | 68 | 42 | 28 |
| Flank wear at 30 min (mm) | 0.12 | 0.22 | 0.35 |
| Surface finish Ra (um) | 1.2 | 1.8 | 2.5 |
| Chip type | Short helical (6-shaped) | Long spiral | Long ribbon |
| Cutting temperature (C) | 580 | 720 | 950 |
| Cutting force Fz (N) | 1850 | 2100 | 2350 |
Optimal Coolant Parameters for Beyond Blast
| Operation | Pressure (bar) | Flow Rate (L/min) | Coolant Type |
|---|---|---|---|
| Finishing steel (Vc > 250) | 200-350 | 8-12 | Semi-synthetic, 6-8% concentration |
| Medium turning steel | 100-200 | 10-15 | Semi-synthetic, 6-8% concentration |
| Roughing steel | 70-150 | 12-18 | Semi-synthetic, 8-10% concentration |
| Stainless steel turning | 150-300 | 10-15 | Synthetic, 8-10% concentration |
| Cast iron turning | 70-120 | 8-12 | Semi-synthetic, 5-7% concentration |
| Superalloy turning | 200-350 | 10-15 | Synthetic, 10-12% concentration |
Application-Specific Benefits
Stainless steel (AISI 316L): Beyond Blast eliminates built-up edge that typically plagues stainless turning. At Vc=140 m/min with KCU25B grade, BUE-free cutting was maintained for the full 55-minute tool life. Flood coolant at the same parameters showed BUE onset at 20 minutes.
Titanium alloy (Ti-6Al-4V): The directed coolant jet reduces the cutting temperature by 35-40%, which is critical for titanium where the low thermal conductivity concentrates heat at the tool tip. Tool life improvement of 80-120% over flood coolant has been documented.
Inconel 718: At Vc=60 m/min with KCU10B, Beyond Blast at 300 bar extended tool life from 12 minutes (flood) to 28 minutes. The high-pressure jet also breaks the long, stringy chips typical of nickel-based alloys into manageable segments.
Toolholder Requirements
Beyond Blast requires dedicated toolholders with internal coolant passages. Kennametal offers the following holder types:
- External turning holders: PCLNR, MWLNR, MVJNR series with Beyond Blast coolant routing
- Boring bars: Internal coolant delivery through the bar body, available in steel and carbide-reinforced versions
- Capto interface: C5 and C6 Capto adapters with integrated coolant channels
- VDI turret adapters: Compatible with VDI 30, 40, and 50 interfaces
Economic Analysis
While Beyond Blast toolholders cost 30-50% more than standard holders, the return on investment is typically achieved within 2-4 weeks of production use. The savings come from:
- 40-60% reduction in insert consumption due to extended tool life
- 15-25% reduction in cycle time due to higher permissible cutting speeds
- Elimination of chip-related downtime (bird-nesting, chip wrapping)
- 30-50% reduction in coolant consumption compared to flood systems
Conclusion
Kennametal Beyond Blast is more than a marketing concept — it delivers measurable, substantial improvements in tool life, surface finish, chip control, and cutting forces across all material groups. The technology is particularly transformative for difficult-to-machine materials like stainless steel, titanium, and superalloys where conventional coolant delivery fails. For shops equipped with high-pressure coolant pumps (100+ bar), Beyond Blast inserts should be the default choice for all turning operations.
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