ASTM A36 A mild steel for general purpose applications. Excellent for mild cold and hot forming, very suitable for general usage in production and maintenance work, and easily welds. Good material for machining, drilling, tapping, punching and grinding. Suitable for applications that do not require the greater strength oh high carbon or alloy steels. The very thin rectangles are generally sold as strip, and size selection is not as great as cold roll C1018. Larger diameters in ASTM A36 are not generally produced, as C1018 hot roll rounds are usually used.