Interpretation of the GB/T 5972 Standard “Scrap Standards for Steel Wire Ropes”
📌GB/T 5972 "Standard for the Scrapping of Wire Ropes"It is an important technical specification in the crane industry. This standard, developed by the National Standards Committee, covers the inspection and scrapping of wire ropes used in cranes.
This standard provides a unified technical basis for designers, inspection agencies, and users. Krude Heavy Industry strictly adheres to the technical requirements of this standard throughout the product development and manufacturing processes.
Scope and Purpose of the Standard
GB/T 5972, “Standard for the Scrapping of Steel Wire Ropes,” primarily specifies the technical requirements and safety criteria related to the scrapping of crane steel wire ropes, and applies to all types of lifting machinery with a rated lifting capacity of 0.5 metric tons or more. This standard not only covers the design and manufacturing of new equipment but also provides clear technical guidance for the inspection, maintenance, and retrofitting of in-service equipment. As a key component of the crane standards system, this standard is harmonized with standards such as the EN 13001 series and ISO 4309, collectively forming a comprehensive system of technical specifications. The technical parameters and safety factor requirements specified in the standard provide designers with a clear basis for design and offer quantifiable criteria for type testing and factory acceptance inspections conducted by third-party inspection bodies.
Core Technical Specifications
According to the technical specifications of GB/T 5972, the design and manufacture of wire rope retirement standards must meet a series of strict technical parameter requirements. These parameters are determined based on extensive experimental data and safety engineering theory, covering the entire process from material selection to structural design. The range of safety factors specified in the standard fully accounts for the fatigue life and ultimate load conditions of lifting machinery under severe operating conditions. In engineering practice, designers must translate the standard’s requirements into specific design parameters to ensure that the load-bearing capacity of each component meets safety requirements.
Comparative Analysis of Key Technical Parameters
| Project | Technical Requirements | Note |
|---|---|---|
| Diameter Reduction | >7% nominal diameter—discontinued | Measurement of the Vertical Mean Value on a Straight Section Without Load |
| Number of Broken Strands | 1 Twist Pitch > 101 TP3T Total Number of Strands (Interlaced Twist) | Co-directional twist > 5% discarded |
| Corrosion Level | Grade 3 (Severe Rust + Pitting) = Scrap | Level 1: Mild / Level 2: Moderate / Level 3: Severe |
| Knots/Rope-Bone Protrusion | Once discovered, it will be discarded | Unrepairable |
| Inspection Frequency | A1–A5: Monthly Visual Inspection / Quarterly Electromagnetic Inspection | A6–A8 Monthly Visual + Electromagnetic |
| Lubrication | Indoor (bimonthly) / Outdoor (monthly) | Compatible with the manufacturer's recommendations |
Inspection Requirements and Frequency
GB/T 5972 sets forth clear requirements for factory inspections, type testing, and periodic inspections of wire rope products. Factory inspections shall be conducted on a unit-by-unit basis by the quality inspection department at the manufacturer’s facility; equipment that passes inspection shall be accompanied by a detailed inspection report and a certificate of conformity. Type testing is conducted when a new product is first put into production, when production is transferred to a different facility, or when major structural changes are made. The periodic inspection interval for in-service equipment is determined based on the duty class and operating environment, and generally does not exceed 12 months. For heavy-duty cranes operating continuously at duty classes A7 to A8, the inspection interval should be appropriately shortened to 6 months.
| Project | Technical Requirements | Note |
|---|---|---|
| Visual Inspection | Surface rust along the entire length / broken wires / deformation | Monthly + Key Areas |
| Diameter Measurement | Vernier caliper 0.02 mm | Monthly + Vertical Average |
| Electromagnetic Testing | Cable Locator LMA+LF | A5 Quarterly / A6 Monthly |
| Lubrication Condition | Surface Oil/Oil-Filled Core | Bimonthly + Shortfall Supplement |
Safety Operation and Management Requirements
Safety operations and daily management play a crucial role in the implementation of GB/T 5972. The standard places particular emphasis on the importance of operator qualifications and training, requiring that all operators undergo specialized training and obtain the appropriate qualifications before being allowed to work. Equipment-using entities should establish a comprehensive equipment record management system to document in detail the entire process of installation, use, maintenance, and inspection. Any identified safety hazards must be addressed in accordance with the corrective action procedures specified in the standard to ensure that the equipment remains in a safe and controlled condition at all times. In addition, the standard sets forth restrictive requirements regarding the use of equipment under extreme operating conditions.
Frequently Asked Questions
Q: What are the criteria for determining when a wire rope is to be scrapped according to GB/T 5972?
Answer: If the diameter is reduced by more than 7%, the number of broken strands exceeds 10%, the corrosion level is Grade 3, or there are knots or the core is exposed—the rope must be discarded.
Q: What are the requirements for electromagnetic testing?
Answer: The LMA has a detection sensitivity of ≥21 TP3T and a speed of 0.3–1.5 m/s. Calibrate before testing.
Q: What are the differences in inspection intervals?
Answer: A1–A5: Monthly visual inspections + quarterly electromagnetic testing. A6–A8: Monthly visual inspections + electromagnetic testing. Increased frequency for outdoor installations.
Q: What are the lubrication requirements?
Answer: Once every two months indoors, once a month outdoors. Compatible with the manufacturer's recommendations.
🔧 Krude Heavy Industry — Specializing in crane design and manufacturing, with products strictly compliant with the GB/T 5972 standard system.
