None. In order for most of the manufacturers (HCA is the only exception I know of)to cover your bow under warranty you must be shooting a minimum of 5 grains per pound of draw weight.

Remember that 5 grains per pound is the bare minimum that you should be shooting. I prefer to have an arrow that weighs 7 or 8 grains per pound. Not only will it be easier on your bow it will also make your bow much much quieter with a heavier arow.