US Patent 9051744 Hand held building tools

The present invention is directed generally to tools that are made, at least in part, more durable, particularly one or more working surface(s) of the tools. For example, various tools such as trowels, knives, and scrapers may be made having at least a portion of their blades heat treated to make at least their working edges more durable and extend their useful lives. For example, in various embodiments, a putty knife, taping knife, or scraper blade may have at least one working surface or edge that has been at heat treated while an area of the blade where a handle is permanently attached is not heat treated.