... 3. hydraulic type 4. economic hydraulic elbow making machine,gorelocker,spiral duct machinery,is for making duct elbows, max. thickness 1.2mm, ... max dia 1000mm.Hydraulic elbow making machine,gore locker,spiral ... : 1.2mm3.2 Suitable material: galvanized steel, aluminum plate,For stainless steel(Max.thickness 1.0mm)3.3 Diameter range ...