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 matched with traction and positive drive lifts and hydraulic lifts, covering the whole life cycle management of 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: ordinary grade, high-precision grade and ultra-high speed special grade according to the applicable scenarios and accuracy grades, adding special technical requirements for high-precision guide rails dedicated to ultra-high speed elevators with rated speed greater than 6m/s, and clarifying the applicable speed range and geometric tolerance limits of guide rails with different accuracy grades; second, greatly improving the mechanical performance and accuracy indicators of the guide rail, tightening the allowable deviation of the straightness, twist and dimensional tolerance of the guide rail working surface, and the straightness deviation limit of the high-precision grade guide rail working surface is tightened by 40% compared with the old version; clarifying the mechanical strength, hardness and toughness indicators of the guide rail material, adding special performance requirements for material-saving high-strength guide rails, and reducing material consumption on the premise of ensuring strength; third, refining the technical requirements for guide rail joints and connectors, clarifying the material, strength and accuracy requirements of guide rail connecting plates and connecting bolts, formulating special limits for guide rail joint gaps and step deviations, and eliminating operation faults such as abnormal noise at guide rail joints and car vibration; fourth, improving the anti-corrosion and surface treatment specifications of guide rails, clarifying the anti-corrosion performance indicators of guide rail surface galvanizing, phosphating and spraying, and formulating special anti-corrosion grade requirements and salt spray test standards for guide rails used in coastal, high-humidity and corrosive environments; fifth, improving the type test and factory inspection rules, adding special test methods and judgment standards for high and low temperature environment performance test, fatigue strength test and wear resistance test of guide rails, clarifying the items, procedures and validity period of type tests, tightening the sampling rules and qualification judgment criteria of factory inspection, mandating that each batch of guide rails must pass the full project accuracy inspection before leaving the factory; sixth, clarifying the packaging, transportation and storage specifications, formulating special requirements for special packaging, fixing, hoisting and transportation in view of the characteristics of long size and easy deformation of guide rails, and clarifying the moisture-proof, rust-proof and deformation-proof specifications for guide rail storage. The implementation of this standard has comprehensively improved the product quality and technical level of China's elevator T-type guide rails, guaranteed the stability and comfort of elevator operation from the level of core guide components, 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 85%. The implementation of this standard will further consolidate the core competitiveness of China's elevator core components in the global market.