Chemical composition for 1045 carbon steel sheet : C% Mn% Si% P S 0.42~0.48 0.6~0.9 0.15~0.35 0.030 0.030 Equivalent Grade: Chinese American German Japanese GB AISI DIN JIS 45# 1045 1.1191 S45C Available sizes Round: Dia. 60300mm Plate: Thickness 16 300mm, width 60- 520mm Delivery condition: Hot rolled or forged Peeled or black surface, annealed or no heat treatment. Properties: A medium carbon steel is used when greater strength and hardness is desired than in the â??as rolledâ?� condition. Extreme size accuracy, straightness and concentricity combine to minimize wear in high speed applications. Turned ground and polished. Applications: Component parts for vehicles, shafts, bushings, crankshafts, connecting rods and parts for the machine building industry and steel for axes, knives, hammers etc. Heat Treatment: Soft annealing: heat to 650-700°C, cool slowly. Hardness after annealing: Max. 207 HB Hardening: 820 - 850 °C Normalizing temperature: 840-870°C Hardness after tempering: