A unique feature about all King Arthur Tool's chains is that they are a full house design which simply means the chain circlet consists of consecutive left and right teeth - the teeth are not separated by skip links common to standard chain saw. All blades have twice the amount of regular teeth resulting in the blade powering its way through the hardest of woods and other soft non ferrous materials. This important feature， combined with the speed of the angle grinder rotating at between 10，000 to 13，000 rpm's provides users with the most efficient and powerful cutting and shaping power tool accessory in the world. Should the blade hit a nail or piece of wire in wood， on most occasions it will cut through the obstruction. If not， the impact will cause the chain to stop while the discs rotate giving the user a warning to stop the angle grinder. This is a major safety feature which virtually eliminates kickback and binding. All chains are easily sharpened with a 5/32 inch (4 millimeter) chain saw file.