This standard is formulated under the jurisdiction of the National Technical Committee for Elevator Standardization of China. It is applicable to T-type guide rails for lift cars and counterweights (or balance weights) of traction and positive drive lifts, covering the whole life cycle management of elevator guide rail design, production, inspection, installation and use. Compared with the old version, the core upgrades of this revision include: first, reconstructing the guide rail classification and accuracy grading system, dividing the guide rails into three categories: cold-drawn type, machined type and high-quality machined type according to the processing technology and accuracy grade, expanding the accuracy grade from the original 3 grades to 5 grades, adding an ultra-high precision guide rail grade dedicated to ultra-high speed elevators, and clarifying the applicable speed range and scenario requirements of guide rails with different accuracy grades; second, greatly improving the mechanical performance indicators of the guide rails, clarifying the material requirements of the guide rail raw materials, mandating the use of high-quality carbon structural steel with phosphorus and sulfur content no higher than 0.030%, and improving the tensile strength, yield strength and hardness indicators of the guide rails; adding the fatigue resistance requirements of the guide rails, stipulating that the guide rails must pass 2 million times of alternating load fatigue tests to ensure the long-term operation stability of high-flow and high-speed elevators; third, refining the accuracy and geometric dimension requirements of the guide rails, tightening the tolerance limits of the straightness, twist and joint machining accuracy of the guide rail working surface, among which the straightness tolerance of the single working surface of the ultra-high precision guide rail is tightened from 0.3mm/m to 0.1mm/m, comprehensively improving the elevator operation stability and low noise performance; fourth, improving the anti-corrosion and surface treatment specifications of the guide rails, clarifying the technical requirements and anti-corrosion grades of surface treatment processes such as galvanizing, phosphating and spraying of the guide rails, and formulating special anti-corrosion performance indicators and test standards for guide rails used in coastal, high-humidity and corrosive environments; fifth, standardizing the type test and factory inspection rules, adding special test methods and judgment standards for the mechanical properties, fatigue strength and anti-corrosion performance of the guide rails, clarifying the items, procedures and validity period of the type test, and improving the sampling rules and qualification judgment criteria of the factory inspection; sixth, refining the specifications for packaging, transportation and storage of guide rails, formulating technical requirements for special packaging, fixing, hoisting and storage in view of the characteristics of long size and easy deformation of guide rails, to avoid deformation and damage of guide rails during transportation and storage. The implementation of this standard has comprehensively improved the product quality and technical level of elevator T-type guide rails in China, guaranteed the stability and safety of elevator operation from the core component level, and also promoted the full integration of China's elevator guide rail products with the international market. China is the world's largest producer and exporter of elevator guide rails, with a global market share of more than 75%. The implementation of this standard will further consolidate the core competitiveness of China's elevator guide rails in the global market.