Your bowl is guaranteed for 12 years against manufacturing defects. If found to be faulty you receive an instant replacement set.
Bias testing is not covered under this warranty.
Dropping a bowls on SMOOTH CONCRETE will cause no damage....drop it on bumpy concrete and it will damage.When you use your bowl it will mark, could chip and scratch,this is 100% normal and does not affect the bowl at all.A bowl hitting another bowl causes no damage...it is always the foreign object in the ditch.