Putty Knife

A putty knife is a tool used when glazing single glazed windows, to work putty around the edges of each pane of glass after the putty has been applied by hand, then smoothed with the knife's blade. The name putty knife is also commonly used for what is more precisely a spackle knife, called a scraper in British English and a spatula in American English, used to scrape surfaces or spread materials such as plaster in general construction and finishing work. Putty and spackle knives are made in standard widths from about one and a quarter inches up to five or six inches, with wider bladed versions up to twelve inches used for drywall work; a stiff blade, typically about one millimeter or 0.040 inches thick, suits scraping, while a flexible blade, typically about half a millimeter or 0.020 inches thick, suits spreading. Because metal blades conduct electricity, they are kept away from electrical components during use, and disposable plastic versions are made for occasional projects.