1. The characteristics of the fuel tank cylinder outer diameter smaller. 2. Do small batches of high precision cold drawn finished raw high accuracy, good surface quality. 4 Steel Cross area more complex. 5. steel pipe superior performance, the metal is relatively dense material used fuel tank cylinder 10 # 0.07 ~ 0.13 0.17 ~ 0.37 0.35 ~ 0.65 ≤0.035 ≤0.035 20 # 0.17 ~ 0.23 0.17 ~ 0.37 0.35 ~ 0.65 ≤0.035 ≤0.035 35 # 0.32 ~ 0.39 0.17 ~ 0.37 0.35 ~ 0.65 ≤0.035 ≤0.035 45 # 0.42 ~ 0.50 0.17 ~ 0.37 0.50 ~ 0.80 ≤0.035 ≤0.035 40cr 0.37 ~ 0.44 0.17 ~ 0.37 0.50 ~ 0.80 ≤0.035 ≤0.035 0.08 ~ 1.10 25Mn 0.22 ~ 0.2 0.17 ~ 0.37 0.70 ~ 1.00 ≤0.035 ≤0.035 ≤0.25 tanks are the most important parts of construction machinery, traditional processing methods are: Broaching cylinder - fine boring cylinder - grinding cylinder. Using rolling method is: Broaching cylinder - fine boring cylinder - rolling cylinder, step three parts, but the contrast in time: grinding cylinder about 1 m in 1-2 days, rolling cylinder 1 meter in about 10-30 minutes. Investment comparison: quilting grinder or mill (tens of thousands - millions), rolling knife (a thousand - tens of thousands). After rolling, the surface roughness of the hole by rolling before Ra3.2 ~ 6.3um buildings reduced to Ra0.4 ~ 0.8 & surface hardness um, hole by about 30%, the cylinder surface fatigue strength by 25%. If only consider the cylinder cylinder life impact, increased by 2 to 3 times rolling process is relatively boring grinding efficiency is about 3 times. The above data shows that the rolling process is efficient and can greatly improve the surface quality of the cylinder. After rolling the cylinder surface is no small sharp edge for a long time and will not damage the movement friction seals or seals, which is especially important in the hydraulic industry. Heavy tanks (HOB) - the use of pressure 14Mpa, thin cylinder (JOB) - the use of pressure 14Mpa, a small circular cylinder (SOB) - Pressure 7Mpa, large circular tanks (ROB, COB) - super high pressure using a pressure 14Mpa round cylinder (HSOB, HROB) - Pressure 21Mpa vehicle lift cylinder cylinder cylinder injection molding machines of various molds, silicone rubber molding machines, die casting machines, balers and other marine cylinder machine cylinder hydraulic cylinder parts for various purposes