Straight seamless steel pipe wall thickness control is a difficult production. At present, the straight seam steel pipe manufacturers to improve the wall thickness in the production of precision uses the methods generally including:1, Tube heating Heating to the average to prevent rapid up and down temperature. Each take-off and landing temperature is to maintain a smooth slow, the maximum rise and fall temperature does not exceed 30 ℃.2, Rolling mill mandrel Average wall thickness of thick wall tube and solid billet make the probability of mandrel bending deformation significantly reduced, can effectively improve the wall thickness of the precision.