一、The cold extrusion connection method of steel bar is a mechanical connection method to connect the two steel bar ends with steel pipe, and then squeeze with portable hydraulic press to make the casing deformation. This method is suitable for industrial and civil construction, high-rise building, foundation engineering, etc. All kinds of reinforced concrete structure of φ2040mm,ⅱ grade steel joint and different diameter steel joint, ribbed steel bar connection can connect vertical, horizontal and any inclination of steel bar, its joint strength, stiffness, toughness is equal to the base metal. (1) Construction preparation 1. Material (1) ribbed steel bars meet the gb1499 standards for reinforced concrete. (2) Casing material meets gb5310 standards. 2. mechanical equipment steel bar extrusion connection complete set of equipment is made up of extrusion connection clamp, ultra high pressure electric oil pump, ultra high pressure oil pipe, suspension (manual hoist) and so on. The steel bar extrusion connection clamp has yj-40 type extrusion clamp, which is used for the docking of ribbed steel bar of φ36~40, yj-32, type extrusion clamp, for ribbed steel bar connection of φ20φ36~32, and yj-23 type extrusion clamp for the docking of ribbed steel bar of φ18φ36~25. 3. working conditions (1) before pressing the steel sleeve and steel bar to remove rust, oil, mud sand, etc., the end of the steel bar should be straight, if there is bending, must be straightened. (2) It is strictly prohibited to mix impurities in the hydraulic system. When connecting and removing the ultra-high pressure hose, the end of the hose should be kept well, and no dust sand should be stuck. 

二、The extrusion process and the sequential steel bar extrusion connection are divided into two processes. The first procedure is to press one end of each steel bar to be connected on the ground and half of the casing as required. The second process is to press half of the joint of the steel bar inserted into the end of the steel bar to be connected, and then press with extrusion clamp, so that the whole joint extrusion work. The extrusion joint must be extruded from the middle of the sleeve in order of marking to the end. 2. steel bar half joint connection process (1) install high pressure tubing and steel bar matching limiter, casing pressure die, and also apply lubricating oil in the pressure die ;(2) press the hand control on the switch, so that the casing to the positive pressure die inner hole, and then press the hand control. Untie the switch ;(3) insert the steel bar top to the limiter to straighten ;(4) press the hand control on the switch to squeeze ;(5) when hear the hydraulic oil overflow sound, then press the hand control down the switch, return the plunger, remove the pressing die ;(6) take out the half casing joint and finish the half joint extrusion operation. 3. the extrusion process of the connecting steel bar (1) insert the half casing into the steel bar to be connected to make the extruder in place ;(2) place the pressing die and pad used with the steel bar ;(3) press the hand-controlled upper switch to squeeze, when the hydraulic oil overflow sound, press the hand-controlled lower switch ;(4) return the plunger and guide plate, install the pad ;(5) press the hand-controlled upper switch to squeeze ;(6) press the hand-controlled upper switch to return the plunger and the pad ;(7) press the hand-controlled upper switch to squeeze, then press the hand-controlled lower switch to return the plunger ;(8) remove the pad, die, extruder, connect. 

三、 Quality standard 1. Ensure that item (1) Steel material meets the standard of steel bar gb1499. (2) The casing material shall have a quality inspection sheet and a certificate of qualification, and the geometric dimensions shall conform to the requirements. (3) The strength of the joint shall be equal to the strength of the same type of steel. For each type of joint, tensile tests shall be carried out in a batch of 500 joints (less than 500 of which are still in one batch), 2. basic item (1) the length of the casing of the casing joint after extrusion, does not reach the paint mark line, the error exceeds 5 mm, this end casing which does not reach the paint mark line is welded with the steel bar, the weld height shall not be less than 5 mm.. (i) Check the outside diameter of the extrusion casing joint with gauge, pass it is qualified, otherwise it is not qualified, press the die again, press again.