The frame of mast derrick that is designed for hydraulic wheel tractor hoist adopt welding of armor plate,its section is oblong armor plate,and its material is HG60.

• 为满足液压轮式通井机的使用要求而设计的桅杆式井架采用板焊结构,主体截面为长方形的方形钢,材料为HG60。