Dummy bar is to guide the slab into the pinch roller essential equipment. The role of dummy bar is blocked when the open casting mold under the mouth, do not leave out the molten steel, the first injection of molten steel in the mold of rapid solidification and dummy head fused segments in the drive roller Driven by the initial solidification of slab pull mold introducing tension leveler, after pulling out of the dummy bar straightening machine, the dummy bar off, casting into the normal state. Therefore, the dummy bar is to guide the slab into the pinch roller essential equipment. Dummy bar Classification: On the curved caster dummy bar through a curved section of the secondary cooling zone arc dummy bar can be divided into rigid and flexible dummy bar dummy bar. Rigid dummy bar: used for carbon steel and low alloy steel billet casting, steel bars made with whole arc of dummy bar. When it guide strand and pull out of the mold after straightening roller, that is decoupled from the slab, parked at the top of the slab roller. Billet does not exist because the problem does not require bulging support and guide in the secondary cooling section, in the secondary cooling zone section requires only a simple guide. Rigid dummy bar system, open casting smooth to prevent breakout irrigate small section of slab due to open water when the dummy bar shake. Simplify the secondary cooling segment support institutions conducive to rapid processing breakout, will help improve the production capacity of the caster. Flexible dummy bar: long pitch dummy bar chain. Long pitch-permanent dummy bar chain hook with automatic decoupling dummy head. Segment itself is curved, with four rollers must straightening machines. Steelmaking arc model and its main properties of high precision, light weight, easy to change. Use it to press the installation and commissioning of various types of continuous casting machines, casting speed evenly, and to ensure no leakage of steel, continuous steel casting machine has played a performance, improve work efficiency, reduce the human and material resources for enterprises to increase efficiency and save money. Arc model is one of the detection tool to check the design requirements of each caster Dan meets bend radius. Caster can also guarantee a one-time throwing the key to successful measurement gauges. Because of the arc model design accuracy requirements are particularly high, generally bend radius requirements for manufacturing precision ± 0.02-0.05, plane requirements for ± 0.05, parallel requirements ± 0.03.