Fatigue cracks are hairline cracks originating in the gullets (slots) or along the flange line in the core.
When dry cutting, fatigue cracks can be caused when the blade overheats. When the blade overheats it will begin to flutter or snake in the cut causing core fatigue. To avoid overheating when dry cutting, do not force the blade into the cut. Allow the blade to spin freely every 30 to 45 seconds, and take shallow cuts no deeper than 1” per pass.
Other causes of core fatigue can be defective flanges that cause the blade to flutter. Improper saw alignment or failing to saw straight with over correcting can cause the blade to jam or twist in the cut.
Inspect blades regularly for fatigue cracking. If cracking is detected the blade cannot be used.