Check the blade to ensure that no cracks have formed at the bottom of the teeth or by the centre hole. The most common reason why cracks are formed is that sharp corners have been formed at the bottom of the teeth while sharpening or that the blade has been used with dull teeth. Discard a blade if cracks are found.
Check that the support flange is not cracked due to fatigue or due to being tightened too much. Discard the support flange if it is cracked.
Ensure the locking nut has not lost its captive force. The nut lock should have a locking force of at least 1.5 Nm. The tightening torque of the locking nut should be 35-50 Nm.
Check that the blade guard is not damaged or cracked. Replace the blade guard if it is exposed to impact or is cracked.