Marathon Circular Saw Blades Features:
IRWIN circular saw blades last longer by design. New heat/vent expansion slots reduce vibration, providing longer life for the blade and straighter cuts for the user. A reinforced shoulder adds durability, and alternating carbide teeth are ground thinner for faster cutting and stay sharp longer.

Every other tooth is ground thinner for fast cuts
Thicker plate design for improved tracking
Reinforced shoulder for durability and impact resistance
Body slots dissipate heat for long blade life