PACIFIC 1045 is a medium carbon steel and therefore has higher strength than 1O18. It is extensively used where the higher strength and toughness of alloy grades are not required. Commercial quality is stocked in smaller diameters. Sizes 3-1/4" through 11" diameter are special quality rough turned oversize bars which have been vacuum degassed, calcium treated and ultrasonic tested for soundness. Forged bars which are rough turned oversize are stocked in large diameter sizes 12" through 18". This medium carbon grade can be through hardened in small sections and can be surface hardened by flame or induction in virtually all diameters. Welding generally requires preheating in the 400°F range.