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Scope of Application and Standard Positioning

GB/T 5974.1-2006 covers standard clamp plates used to secure the end of a wire rope to a drum or structural member. The clamp plate is a steel plate (or cast steel component) with a machined semi-circular groove on its underside that matches the wire rope diameter, and is tightened against the drum surface with bolts. The clamping principle relies on the friction force between the clamp plate and the drum surface to hold the rope in place — combined with the two safety wraps on the drum (tension attenuates to approximately 20% at the rope end after two wraps), the load on the end fastening point is significantly reduced.

Three types are defined: Type A (single-bolt fixing, wire rope diameters 6–14 mm), Type B (two-bolt fixing, 16–28 mm), and Type C (four-bolt fixing, 32–60 mm). The groove radius is determined by the nominal rope diameter d: R = (0.53–0.55)d, ensuring proper seating of the rope in the groove after clamping. The clamp plate width B ≥ 2.5d ensures adequate lateral coverage of the rope. The standard includes detailed dimensional tables for more than 30 specifications ranging from 6 mm to 60 mm. Kelude supplies clamp plates in all specified sizes.

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Material and Manufacturing Technical Requirements

Clamp plates are manufactured from Q235B steel (general-purpose applications), Q345B steel (high-load applications), or ZG270-500 cast steel (for cast plates). Cast plates must be free from porosity, shrinkage cavities, sand inclusions, and cracks. Manufacturing precision requirements: groove radius tolerance H12 (+0.12 mm for R6–R30), surface roughness Ra ≤ 12.5 μm. Bolt hole center distance tolerance is ±0.2 mm to ensure accurate alignment with the tapped holes in the drum. Bolt holes are through-threaded (metric coarse thread, M6–M30) with a 6H thread tolerance.

Surface treatment: galvanizing (hot-dip zinc layer ≥ 15 μm) or blueing/phosphating. A sampling rate of 3% per batch, with a minimum of three pieces, is subjected to a breaking force test — a load of 1.5 times the wire rope's minimum breaking force is applied and held for 5 minutes without cracking or failure. Slight plastic deformation (not exceeding 5% of the groove depth) is permissible after testing.

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Installation, Operation, and Maintenance Requirements

The installation method recommended by the standard: the wire rope is wound at least two safety wraps around the drum before the rope end is placed in the clamp plate fixing groove. The clamp plate straddles the rope — the groove seats against the rope and bolts pass through the plate holes into the tapped holes in the drum. Bolts are tightened evenly in a diagonal sequence in 2–3 passes (M16: approx. 150 N·m, M20: approx. 250 N·m, M24: approx. 400 N·m). At least two clamp plates are installed per rope end (spaced ≥ 50 mm apart), with the orientation ensuring that rope tension presses the rope into the groove rather than pulling it out.

Monthly inspections should check for loose clamp plate bolts (bolt loosening is the most common cause of fixing failure — crane vibration gradually backs off the bolts), corrosion on the clamp plate, and wear at the contact area between the plate and the rope. The marking line method is the most practical way to detect bolt loosening: after installation, draw an alignment line across the bolt head and the clamp plate surface — any bolt rotation is immediately visible as a misaligned line. When replacing the wire rope, always replace the clamp plates and bolts as well. Welding repair of clamp plates is strictly prohibited.

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Standard Comparison and Application Recommendations

GB/T 5974.1-2006 (standard clamp plates) and GB/T 5974.2-2006 "Wire Rope Clamp Plates – Part 2: Grooved Clamp Plates" together form a complete standard system for wire rope end fastening. Standard clamp plates are suitable for conventional crane operating conditions with a rope deflection angle ≤ 2°, offering a simple structure, easy installation, and lower cost. Selection should be based on the wire rope diameter, drum configuration, and specific operating conditions.

For maintenance management, the marking line method is strongly recommended for checking bolt loosening — it eliminates the need to torque-check every bolt individually. When replacing the wire rope, it is advisable to replace the clamp plates and bolts simultaneously, as used plates have permanent indentations in the groove and bolts have undergone slight plastic deformation, creating a risk of fixing failure if reused.

Kelude Heavy Industry: Engineered for the Toughest Lifting Challenges

Kelude Heavy Industry is a specialized manufacturer of heavy-duty industrial cranes and hoisting solutions. Our product line is built around the specific demands of modern manufacturing, logistics, and infrastructure—delivering equipment that prioritizes safety, uptime, and long-term value. From single-girder cranes for light assembly work to double-girder systems for high-capacity process handling, every unit is designed, fabricated, and tested in-house to meet rigorous international standards.

Why Kelude Stands Apart in Overhead Material Handling

We don't just build cranes; we engineer lifting solutions. Our approach starts with a deep analysis of your operational workflow—load cycles, headroom constraints, duty classification, and future expansion plans. This ensures the crane you receive isn't a generic unit, but a tailored fit for your facility. Key differentiators include:

• Duty-cycle rated design: All structural and mechanical components are selected based on FEM/ISO duty classifications, not just static load limits.
• Precision engineering: Finite element analysis (FEA) is used on all primary structures to optimize weight while maximizing rigidity and fatigue life.
• Integrated safety systems: Standard features include overload protection, anti-sway control, and variable-frequency drives (VFD) for smooth, precise load positioning.
• Global compliance: Our manufacturing processes and quality management systems align with ISO 9001 standards, and our crane designs meet ISO 4301 and IEC 60204-32 requirements.

Whether you need a single point of responsibility for a turnkey installation or a custom-engineered attachment for a unique process, our team provides complete documentation, load test reports, and after-sales support.

Q: What is the typical lead time for a standard single-girder crane?
A: For a standard crane within our catalog range, lead time is typically 6-8 weeks from order confirmation. Custom-engineered solutions may require 12-16 weeks, depending on complexity.

Q: Do you provide installation services?
A: Yes, we offer full turnkey installation by our own certified crews or through our authorized local partners. This includes site survey, foundation design assistance, crane erection, and load testing.

Q: Can your cranes be integrated with existing building structures?
A: Absolutely. Our engineers can design the crane runway and support steel to match your existing columns and roof trusses. We frequently work on retrofit projects where the building is already in place.

Q: What is the warranty period for Kelude cranes?
A: We provide a standard 24-month warranty on all structural and mechanical components, and a 12-month warranty on electrical parts. Extended warranty options are available upon request.

Q: How do you ensure the quality of your cranes?
A: Every crane undergoes a rigorous quality control process, including material traceability, non-destructive testing (NDT) on critical welds, and a full-load test with a certified load cell. We also provide comprehensive documentation, including CE declaration of conformity and test certificates.

Q: Can you provide cranes that meet specific international standards?
A: Yes, our cranes are designed to comply with ISO 4301 for classification, IEC 60204-32 for electrical equipment, and ISO 12480 for safe use. We can also adapt designs to meet local codes such as ASME B30.20 in the US or specific EU directives.

Q: What kind of after-sales support do you offer?
A: We offer a comprehensive after-sales program including spare parts supply, preventive maintenance contracts, and technical support via phone or video call. Our global service network ensures rapid response times.

Q: Are your cranes suitable for outdoor use?
A: Yes, we can equip cranes with weatherproof enclosures, corrosion-resistant paint systems, and specialized components like sealed motors and stainless steel control panels for outdoor or harsh environment applications.

Q: Can you help with the design of the crane runway?
A: Yes, our engineering team can provide complete runway beam design calculations, including wheel load data and deflection criteria, to ensure the supporting structure is correctly sized.

Q: Do you offer financing options for crane purchases?
A: We can assist in arranging financing through our partner financial institutions for qualified buyers. Please contact our sales team to discuss the options available in your region.

Q: What is the maximum span available for a double-girder crane?
A: Our standard maximum span for a double-girder crane is 40 meters (131 ft). For spans beyond this, we conduct a detailed engineering study to ensure structural integrity and cost-effectiveness.

Q: Can the cranes be operated by remote control?
A: Yes, all our cranes can be supplied with a radio remote control as an option. We offer both standard industrial remotes and advanced models with load display and diagnostic functions.

Q: How often should a crane be inspected?
A: We recommend a thorough inspection at least once a year, or more frequently for heavy-duty applications. Our service team can set up a customized maintenance schedule based on your crane's duty cycle and operating environment.

Q: What safety features are standard on your cranes?
A: Standard safety features include overload protection, limit switches for hoist and trolley travel, emergency stop buttons, and audible/visual travel alarms. Additional features like anti-sway and zone control are available as options.

Q: Can you provide cranes with a higher lifting capacity than 100 tons?
A: Yes, for special projects we can engineer cranes with capacities up to 300 metric tons. These are typically custom-designed and require a detailed site assessment.

Q: Do you offer training for crane operators?
A: Yes, we provide both on-site and classroom-based training programs for operators and maintenance personnel. Our training covers safe operating practices, daily checks, and basic troubleshooting.

Q: What is the difference between a wire rope hoist and a chain hoist?
A: Wire rope hoists are generally faster, offer higher lifting heights, and are better suited for heavy-duty or continuous operation. Chain hoists are more compact, cost-effective for lighter loads, and have a simpler design. We can advise on the best option for your specific application.

Q: Can your cranes be used in areas with high humidity or washdown requirements?
A: Yes, we offer stainless steel control panels, IP66-rated electrical enclosures, and special paint systems that withstand frequent washdowns and high humidity environments, common in food processing and pharmaceutical industries.

Q: How do you handle spare parts for older crane models?
A: We maintain a comprehensive archive of drawings and parts lists for all models we have produced. Even for older cranes, we can manufacture replacement parts to the original specifications.

Q: What is the expected lifespan of a Kelude crane?
A: With proper maintenance and operation within the specified duty cycle, a Kelude crane is designed to last 20-30 years. The structural components are designed for fatigue life, and mechanical parts can be replaced as needed.

Q: Can you integrate the crane with our existing automation system?
A: Yes, our cranes can be equipped with various communication interfaces (Profibus, Profinet, EtherNet/IP) and can be controlled via PLC. We work with your automation team to ensure seamless integration.

Q: Do you provide a load test certificate for each crane?
A: Yes, every crane is load-tested to 125% of its rated capacity before shipment, and a detailed load test certificate is included in the documentation package.

Q: Can you help with the installation of the crane runway beams?
A: While we typically supply the crane itself, we can provide detailed installation drawings and technical supervision for the runway beam installation. We can also recommend qualified local contractors.

Q: Is it possible to have a crane with a cantilever on one side?
A: Yes, we offer cranes with a cantilever extension on one or both ends of the bridge. This is useful for serving a workstation or a loading area beyond the main runway span.

Q: How do you ensure the safety of the crane during an earthquake?
A: For seismic zones, we can design the crane and its anchoring system to withstand specified seismic loads according to local building codes. This includes reinforced structural connections and special end carriage designs.

Q: Can you provide a crane with a double hoist configuration?
A: Yes, we can design cranes with two independent hoists on the same bridge, allowing for tandem lifting of long or awkward loads. This is common in steel service centers and precast concrete plants.

Q: What is the maximum lifting speed of your hoists?
A: Lifting speed depends on the hoist size and duty cycle. For smaller hoists, speeds can be up to 10 m/min, while larger hoists typically operate at 2-5 m/min. Variable frequency drives allow for precise speed control across the entire range.

Q: Do you offer a maintenance contract with guaranteed response time?
A: Yes, we offer different levels of service contracts, including one with a guaranteed 24-hour response time for emergency breakdowns. Our service level agreements (SLAs) are tailored to your operational needs.

Q: Can the crane be painted in our corporate colors?
A: Absolutely. We offer a wide range of RAL colors for the crane finish. Please specify your preferred color code when placing an order.

Q: What kind of documentation is provided with the crane?
A: Each crane comes with a complete documentation package, including: general arrangement drawings, electrical schematics, operation and maintenance manual, spare parts list, and all relevant test certificates.

Q: How do you handle the logistics for international shipping?
A: We have extensive experience in exporting cranes worldwide. We handle all packing, container loading, and shipping documentation. We can also arrange for project cargo shipping for larger cranes.

Q: Can you provide a crane that is compatible with an existing runway system?
A: Yes, we can design a new crane to fit an existing runway system. We will need the runway beam dimensions, rail size, and existing wheel load data to ensure a proper fit.

Q: What is the noise level of your cranes during operation?
A: We design our cranes to minimize noise, using helical gearboxes and sound-dampening materials where possible. Typical noise levels are below 80 dB(A) at a distance of 1 meter from the crane, depending on the configuration.

Q: Can you supply a crane with a special hook height?
A: Yes, the hook height can be customized to suit your building height and process requirements. We can maximize hook height by using a low-headroom design or by adjusting the bridge and trolley configuration.

Q: Do you offer a remote monitoring service for cranes?
A: Yes, we offer an IoT-based remote monitoring system that tracks key parameters like motor temperature, brake wear, and number of starts. This data is accessible via a secure web portal for predictive maintenance.

Q: What is the process for getting a quote for a custom crane?
A: Please provide us with your load capacity, span, hook height, duty cycle, and any specific requirements. Our engineering team will review the information and provide a detailed quotation with technical specifications.

Q: Can you provide a crane with a rotating trolley?
A: Yes, for special applications like mold handling, we can equip the trolley with a slewing mechanism that allows the load to be rotated up to 360 degrees.

Q: How do you ensure the quality of the electrical components?
A: We use components from leading brands like Schneider Electric, Siemens, and ABB. All electrical panels are built and tested according to IEC 60204-32 standards.

Q: Can you provide a crane with a higher duty cycle for continuous operation?
A: Yes, we can design cranes for duty class M8 (A8) per ISO 4301, which is suitable for continuous, heavy-duty operation. This involves using larger motors, heavier gearboxes, and reinforced structures.

Q: What is the maximum ambient temperature for your cranes?
A: Standard cranes are designed for ambient temperatures from -20°C to +40°C. For higher temperatures, we can provide special cooling systems and high-temperature lubricants, extending the range up to +60°C.

Q: Can you provide a crane with a special paint system for offshore use?
A: Yes, for offshore or marine environments, we offer a specialized paint system with a zinc-rich primer and polyurethane topcoat, providing excellent corrosion resistance in salt-laden atmospheres.

Q: Do you offer a buy-back or trade-in program for old cranes?
A: We can sometimes offer a trade-in value for your old crane, depending on its condition and model. Please contact our sales team to discuss the possibilities.

Q: Can you provide a crane with a special voltage and frequency?
A: Yes, we can customize the electrical system to any voltage and frequency, including 230V, 380V, 415V, 480V, and 50 or 60 Hz. Please specify your local power supply specifications.

Q: What is the standard warranty period for the electric motor?
A: The standard warranty for electric motors is 24 months from the date of commissioning, but not exceeding 30 months from the date of shipment. This covers any manufacturing defects.

Q: Can you provide a crane with a special length of

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A: Related Standards

• GB/T 22437.1 — Couplings for Cranes, Part 1
• GB/T 6974.1 — Crane Terminology, Part 1

FAQ: Wire Rope Clamping Plates

Q: What is the purpose of the clamping plate, and why can't it be replaced with another method?

A: The clamping plate secures the wire rope end to the drum, using the friction force between the plate and the drum surface to hold the rope firmly in place. Welding or knotting are not acceptable substitutes — welding severely compromises the rope's strength and flexibility, while knotting creates stress concentration points and prevents precise positioning.

Q: Why is it recommended to replace the clamping plate at the same time as the wire rope?

A: The clamping plate undergoes irreversible changes during the service life of the previous rope: grooves become indented, bolts experience slight plastic deformation, and micro-cracks may develop. Since the clamping plate costs only a few percent of the wire rope price, replacing both together is a small price for peace of mind.

Q: How is the tightening torque for clamping plate bolts determined?

A: Torque is determined by bolt specification and material grade (marked on the bolt head, e.g., 8.8, 10.9). General guidelines: M10 — approx. 40–50 N·m; M12 — approx. 70–80 N·m; M16 — approx. 150–180 N·m; M20 — approx. 250–300 N·m; M24 — approx. 350–450 N·m. Always use a torque wrench, and after installation, draw an alignment line across the bolt head and clamping plate surface for easy inspection.

Q: When must a clamping plate be scrapped?

A: Scrapping is required when groove wear depth exceeds 2 mm, overall thickness is reduced by more than 20% (due to corrosion or wear), any cracks are present, bending or twisting deformation is visible, or bolt hole threads are damaged to the point that the specified tightening torque cannot be achieved.