Two Ways to Build a Diamond Blade
The diamond segments on a blade must be securely attached to the steel core. Two primary methods accomplish this: laser welding and sintering (also called hot pressing). The construction method significantly impacts blade safety, performance, and price.
Sintered (Hot Pressed) Diamond Blades
How Sintering Works
In sintered blades, the diamond segments are formed by mixing diamond powder with metal bond powder, placing the mixture in a mold, and heating it under pressure (typically 700-900°C) until the metal particles fuse together. The segment is then attached to the steel core, typically using a lower-temperature braze or mechanical bond.
Characteristics
- Segment attachment: Brazed or mechanically bonded to the steel core
- Manufacturing cost: Lower — simpler process, less energy intensive
- Segment height: Typically 7-8mm (limited by brazing process)
- Maximum operating speed: Lower — limited by bond strength
Best Applications
- Dry cutting at moderate speeds
- Light to medium-duty construction
- DIY and occasional professional use
- Smaller diameter blades (up to 9")
Limitations
- Segment can detach under heavy load or overheating
- Not suitable for wet cutting (water weakens the braze joint)
- Lower maximum RPM rating
- Shorter segment height means shorter overall blade life
Laser Welded Diamond Blades
How Laser Welding Works
In laser welded blades, a high-powered laser beam melts both the segment base and the steel core, creating a metallurgical fusion bond between the two. This is essentially "welding" the segment to the core — creating a joint stronger than the surrounding materials.
Characteristics
- Segment attachment: Metallurgical fusion weld — segment and core become one piece
- Manufacturing cost: Higher — requires laser welding equipment and expertise
- Segment height: Can be 10-12mm or taller — weld strength supports larger segments
- Maximum operating speed: Higher — weld joint exceeds steel core strength
Best Applications
- Heavy-duty professional construction
- Wet cutting applications
- High-speed cutting operations
- Large-diameter blades (12"-20"+)
- Critical applications where segment loss is unacceptable
Advantages
- Segment will not detach before the blade is worn out
- Wet cutting safe: Water doesn't affect the weld integrity
- Higher RPM ratings for faster cutting
- Taller segments mean longer blade life (more diamond to wear through)
- Higher safety margin — exceeds EN13236 requirements
Side-by-Side Comparison
| Feature | Sintered Blade | Laser Welded Blade |
|---|---|---|
| Segment attachment | Braze/mechanical | Laser fusion weld |
| Joint strength | Good | Exceptional |
| Wet cutting safe | No | Yes |
| Max operating speed | Standard | High |
| Segment height | 7-8mm | 10-12mm+ |
| Blade life | Standard | 40-60% longer |
| Safety margin | Adequate | Superior |
| Price | $ | $$-$$$ |
| Best for | Dry cutting, lighter duty | Professional heavy-duty, wet cutting |
The Safety Factor
The primary reason to choose laser welded blades for professional applications is safety. A detached segment from a sintered blade spinning at 6,000 RPM becomes a high-velocity projectile capable of causing serious injury. Laser welded segments stay attached until the blade is fully worn out — eliminating this hazard.
How to Identify Construction Method
- Laser welded: Often marked "LASER WELDED" or "LW" on the blade
- Sintered: May say "SINTERED" or have no specific marking
- Visual inspection: Laser welds show a fine, precise weld line at the segment-to-core junction
- Price: Laser welded blades typically cost 30-60% more
Conclusion: Laser Welded for Professional Work
For professional contractors working on demanding job sites, laser welded diamond blades offer significant advantages in safety, blade life, and versatility. The higher initial cost is offset by longer service life and elimination of segment-loss hazards. For lighter-duty or dry-cutting-only applications, quality sintered blades provide adequate performance at a lower price point.
At JKINGS Tools, we manufacture both laser welded and sintered diamond blades. Our laser welded series uses precision fiber laser welding systems with full penetration welds that exceed EN13236 standards. Contact us for blade construction specifications and recommendations.
