Weldable Hot Rolled Steel Plate (1/4 x 4 x 4, Steel) Bulb Industries square steel plates work great for any type of project where a steel plate is needed. These plates are weldable, machinable, and paintable. Cut to a convenient size each set includes 2 square steel plates 4 inch by 4 inch by 1/4 inch thick. Made in the USA with from USA hot rolled steel flats that are saw cut and de-burred and ready to use. Steel comes pickled and oiled (P&O) for a rust resistant finish.