Tools Guide: How to Use Vacuum Brazed Diamond Core Bits on Tile & Stone

Drilling hard materials like porcelain, ceramic, marble, or granite requires precise matching between bit design, machine speed, and operator technique. Most field failures happen when one of these components is mismatched.

Technical Specifications & Operational Guidelines

Operational Parameter	Recommendation / Guideline
Minimum Speed	2,500 RPM
Optimal Power Tool	High-speed Angle Grinder (Preferred) or Corded Hand Drill
Allowed Drilling Mode	Rotation ONLY (Never use Hammer/Impact mode)
Starting Angle	45° (to establish initial crescent notch)
Primary Substrates	Porcelain, Ceramic, Vitrified Tile, Marble, Granite, Natural Stone
Secondary Substrates	Glass, Non-reinforced Concrete (Occasional use)

How Vacuum Brazed Core Drill Bits Work

• Immediate Cutting Action: Delivers an aggressive, fast bite straight out of the box without requiring initial dressing or breaking in.
  
  
• Core Body Steel: DIASHARK uses 45 steel for larger cores without wax plugs, and 40Cr steel for smaller sizes.
  
  
• Internal Wax Plugs: Sizes $\le 18\text{ mm}$ incorporate internal cooling wax. Once this wax is fully depleted, the remaining service life depends on operator technique and current diamond wear.
  
  

Machine Selection: Angle Grinders vs. Hand Drills

Crucial Rule: Always check machine speed under load—not just physical connection compatibility.

• Angle Grinder (Recommended): Maintains consistently high rotational speeds (>2,500 RPM) under cutting pressure, ensuring diamond grit continues chipping rather than rubbing and glazing.
  
  
• Corded Drill: Acceptable if the motor provides higher speeds and maintains torque under load.
  
  
• Cordless Drill: Not recommended for hard porcelain or thick granite; speed drops significantly under resistance, accelerating thermal wear.
  
  

Angle Grinder Speed Reference

• Below 100 mm Diameter: Target ~6,000 RPM (Max: 11,000 RPM).
  
  
• 100 mm Diameter and Above: Target ~3,000 RPM (Max: 6,000 RPM).
  
  

Step-by-Step Drilling Technique for Porcelain Tile

Warning: Never use hammer or impact mode. Impact action shatters brazed diamond bonds and causes immediate tile cracking.

1. Start at 45 Degrees: Hold the machine firmly and touch one side of the diamond rim to the tile face at a 45° angle to grind a small, crescent-shaped groove.
   
   
2. Pivot to 90 Degrees: Once the notch is anchored, slowly bring the tool up into the perpendicular position while maintaining steady, moderate pressure.
   
   
3. Use an Orbital Motion: Apply a slight, controlled rocking motion during deep cuts. This creates pathways for dust/swarf ejection and keeps fresh diamond edges exposed.
   
   
4. Avoid Excessive Feed Force: Let the diamond grit cut freely. Forcing the bit generates rapid heat buildup and glaze without improving penetration speed.
   
   

Clearing Blocked Drill Bits

• Bits $\ge 19\text{ mm}$ (Side Opening): Insert a screwdriver or long nail through the side slot to push out compacted debris. Lightly tap with a hammer if tightly jammed (avoid hitting the diamond rim).
  
  
• Bits $\le 18\text{ mm}$ (Wax Plug): Lightly tap the outer steel casing with a wrench to vibrate loose compacted swarf.
  
  

Quick Troubleshooting Guide

• Bit Cuts Slowly: Verify RPM is above 2,500. Inspect core for internal debris blockages. Reduce feed pressure.
  
  
• Excessive Heat Buildup: Check machine speed, reduce downward pressure, and clear internal core build-up immediately.
  
  
• Tile Chipping/Cracking at Start: Shift from direct 90° entry to a 45° angled start to anchor the cut smoothly.
  
  
• Bit Binds Suddenly: Stop cutting instantly. Inspect the core cylinder for compacted masonry or tile chips.