Whose signature is needed on co-owner savings bonds?

Over the years we have purchased Series E/EE bonds. The bonds have been purchased on a co-owner basis with our grandchildren as co-owners. If we redeem them will our minor grandchildren need to sign them as well? Tom's response Either the owner or co-owner of a savings bond can cash it without the signature of the other. You should have no problem cashing them without the signatures of your grandchildren.