The cold extrusion sleeve is a connection formed by inserting the steel bar to be connected into the extrusion nut and squeezing the nut with extrusion pliers to cause a shape change and close pressing with the surface of the ribbed steel bar. Compared with the traditional steel bar lapping and welding process, this method has the characteristics of stable and reliable connector quality, not affected by the environment, can be constructed within 24 hours, and has the characteristics of strong seismic performance and low temperature resistance of the connector
1. Material requirements: Cold-extruded steel bar sleeves should be manufactured using raw materials quenched and preferred 20# steel, and their hardness and physical properties should meet the specified standards.
2. Appearance inspection: the appearance of the cold-extruded steel bar sleeve is flat, with no obvious shortcomings, no burrs, bubbles and other surface shortcomings;3. Specification accuracy: Cold-extruded steel bar sleeves should meet the specified standards and specified dimensional accuracy, including diameter, nominal diameter, thickness and other aspects;
4. Mechanical properties: compressive strength, tensile strength, elongation and other aspects need to meet the specified standards.
5. Corrosion resistance: Wear-resistant coatings or other efficient engineering and technical measures should be used to ensure service life and corrosion resistance.
All in all, the requirements for cold-extruded steel bar sleeves in railway line standards are very strict to ensure that their quality and safety characteristics meet the standards and provide reliable application for railway line construction and operation