Success Case: Custom 6-Flute Internal Coolant Reamer for Stainless Steel Deep Hole Machining

Project Background: Challenges in Stainless Steel Deep Hole Machining

The customer, a high-end hydraulic equipment manufacturer, required machining stainless steel deep holes (D12.5H7, 85mm depth) with Ra0.4 surface roughness and ±0.005mm hole tolerance.
The original process using standard reamers faced the following pain points:

• Poor chip evacuation: Chip clogging caused tool chipping, with tool life limited to ~600 holes.
• High thermal deformation risk: Traditional external cooling failed to dissipate heat, causing ±0.015mm hole tolerance fluctuations due to temperature rise.
• Low efficiency: Single-piece machining time reached 2.5 minutes, affecting production line rhythm.

Technical Solution: Custom CARBIDE REAMER 6FL-COOLANT Design

Based on customer requirements, we developed the CARBIDE REAMER 6FL-COOLANT (D12.5x35x85xD12x6FL), with the following key design highlights:

1. 6-Flute High-Efficiency Structure

• 6FL (6 Flutes) design improves cutting stability, with optimized flute spacing at a 58° helix angle to reduce vibration.
• Parabolic chip flute (D12→D12.5) increases chip space by 40%, preventing clogging in deep-hole machining.

1. Single-Center Internal Coolant Design

• Center coolant hole (EW1.8xDP1.2): A single large-diameter coolant channel (1.8mm) at the tool axis delivers coolant directly to the cutting zone (80bar pressure, 1.2mm from the cutting edge).
• Negative pressure chip evacuation: The center hole creates a vacuum effect, accelerating chip removal and reducing adhesion on hole walls (critical for stainless steel).

1. Precision Manufacturing Process

• Key dimensional tolerances:
  • D12.5H7 (-0.005mm) (hole diameter)
  • D12h6 (±0.003mm) (shank diameter)
  • 35mm cutting length (±0.02mm)
• Surface treatment: TiAlN nano-coating (3.2μm thickness) enhances wear resistance and thermal stability.

1. Anti-Vibration Optimization

• Edge honing adjusted to 0.02mm, combined with asymmetric helical flutes (Helix Angle 35°/38°) to minimize cutting impact.

Application Results: Dual Breakthroughs in Efficiency and Precision

Customer testing showed:

• Improved Hole Accuracy: Tolerance stabilized at ±0.003mm, meeting H7 assembly standards.
• Achieved Surface Roughness: Ra≤0.4μm, eliminating secondary polishing.
• Enhanced Efficiency: Single-piece machining time reduced to 1.6 minutes, improving efficiency by 36%.
• Cost Reduction: Per-hole cost dropped by 42%, saving over $180,000 annually.

Customer Feedback:
“This 6-flute internal coolant reamer completely solved our heat dissipation and chip evacuation challenges in stainless steel deep-hole machining. Tool life extended 3x, and hole stability eliminated frequent equipment adjustments, boosting our line efficiency directly!”

Technical Highlights Summary

• Single-Center Coolant Advantage: Direct coolant delivery (1.2mm from cutting edge) extends tool life to 1,800 holes.
• Anti-Vibration Design: Asymmetric helical flutes (35°/38°) + 0.02mm honing reduce vibration-induced tolerance deviations.
• Rapid Validation: Trial solutions within 72 hours, first-batch delivery within 3 weeks.