Rebar Cold Extrusion Technology The Cold Extrusion Machine is made up by a hydraulic Clampy with Cold Pressing Dies and Hydraulic Oil Pump.� Only 1 â?? 3 kw power of oil pump, which is not limited by power capacity, has flexible structure and suitable for operation on several machines. Advantages: No professional and experienced worker needed, able to connect changed steel bar of different diameters. Save 80% of connector steel consumption. Only needs 1 3m to stamp each connector, which is about ten times faster than ordinary welding. No flammable gases, not affected by rainy or cold weather. Relieve congestion of the connecting point, facilitated concrete pouring.