it is the most ideal material to make high-grade notebook, desk calendar, hung calendar, single and double spring, and colored clip, etc, which are the replacing products of documents, and other office products. Material: Qualified carbon steel 　Paint: Macro-molecule heat-resistant paint developed by our factory. 　Color: White, black, red, orange, yellow, green, and blue, etc. 　Spec: 0.50--1.50m/m Coat: 0.05--0.07m/m　　 Tensile strength: 650±100N/mm 　Rebounding angle: 55°±10° If the client has special requirement, please mail us to discuss the standard, and we ensure the quality, quantity and timely delivery