Crane Brake General Requirements & Technical Specifications
JB/T 7687.1-2008 "Lifting Appliances — Brakes — Part 1: General Requirements" is the general technical standard for crane brakes. It specifies the classification, technical requirements, performance parameters, test methods, and inspection rules for crane brakes, and is applicable to all types of crane brakes including shoe brakes, drum brakes, disc brakes, and cone brakes.
JB/T 7687.1-2008 serves as the foundational general-purpose section of the crane brake standard series, providing unified specifications for general requirements and technical provisions. As a critical safety component of cranes, the design and manufacturing quality of brakes directly affects operational safety. This article provides a systematic interpretation of the core technical requirements set forth in the standard.
Standard Scope and Brake Classification
JB/T 7687.1-2008 is the foundational part of the crane brake standard series, applicable to the design, manufacturing, and inspection of brakes used in all mechanisms of overhead traveling cranes, gantry cranes, tower cranes, mobile cranes, and jib cranes. The brake is one of the most critical safety components on a crane — it is responsible for reliably stopping and holding the suspended load (or mechanism) at any position. The standard classifies crane brakes by structural type: shoe brakes (brake shoes arranged symmetrically to clamp the brake wheel), drum brakes (brake shoes expand outward to press against the inner surface of the brake drum), disc brakes (friction linings clamp the brake disc axially), and cone brakes (conical friction surfaces press radially). By working condition, brakes are classified as normally closed type (closed by spring force, opened by electromagnetic or hydraulic force — the most common type used on cranes) and normally open type (closed by operating force, opened by spring force).
Technical Requirements
The standard imposes comprehensive technical requirements on crane brakes: Braking torque — the braking torque of the brake under rated working conditions must not be less than 1.5 times the required braking torque of the hoisting mechanism, or 1.25 times for the travel mechanism. For hoisting mechanisms handling molten metal, the braking torque safety factor must be ≥2.0. Brake spring — the closing spring of the brake must be made of high-quality spring steel (60Si2Mn or 50CrVA), quenched and tempered at medium temperature. After 300,000 compression cycles under maximum working load, the permanent deformation of the spring must not exceed 1% of its free height.
Brake lining — the friction coefficient of the brake lining (shoe or friction pad) must remain stable between 0.35 and 0.45 across the working temperature range (-20 to +200°C). The wear life of the lining must be no less than 200,000 braking cycles under normal operating conditions. Linings must be replaced when wear exceeds 50% of the original thickness. Brake wheel/disc — the surface hardness of the brake wheel or brake disc must be HB≥280 (medium carbon steel with surface hardening treatment). The surface roughness of the brake wheel working face must be Ra≤1.6μm.
Brake Adjustment and Maintenance
The standard requires that brake adjustment and maintenance meet the following provisions: Brake clearance — the clearance between the brake shoe and the brake wheel (in the open position) must be uniform, with a per-side clearance of 0.5–1.5mm (the clearance increases with the brake drum diameter). Brake spring adjustment — the braking torque is set by adjusting the spring compression. The spring compression must be adjusted in accordance with the manufacturer's manual; arbitrarily increasing the compression to obtain higher braking torque is prohibited (excessive braking torque causes braking impact and damage to transmission components). Brake release stroke — the release stroke of the electromagnet or hydraulic push rod must be adjusted to the minimum stroke at which the brake shoes fully disengage from the brake wheel. Excessive stroke increases release time, while insufficient stroke causes the brake shoes to drag against the brake wheel.
Testing and Inspection
The standard specifies the following tests for brakes: Braking torque test — a gradually increasing torque is applied to the brake wheel (disc) until the brake slips; the torque value at the moment of slip (i.e., the actual braking torque) is recorded and must be no less than 1.5 times the specified value. Thermal fade test — after 10 consecutive braking cycles (at 30-second intervals), the braking torque of the 10th cycle must not be lower than 80% of the 1st cycle (verifying the high-temperature stability of the friction lining). Fatigue life test — after 100,000 continuous open-close cycles under rated conditions, the brake is inspected for wear and deformation of all components. Each brake must undergo a braking torque test and visual inspection before leaving the factory to ensure freedom from cracks and casting defects. Kelude cranes are equipped with brakes that comply with JB/T 7687.1, and the hoisting mechanism is fitted with a dual brake system, allowing either brake to independently hold the rated load should the other fail.
Crane Brake Technical Requirements Reference Table
The reference table below summarizes the core parameter configurations of the crane brake technical requirements for the convenience of selection and operating personnel.
Kelude Heavy Industry: Overhead & Gantry Crane Solutions
Kelude Heavy Industry specializes in the design, engineering, and manufacturing of heavy-duty overhead cranes, gantry cranes, and electric hoists. With a strong focus on safety, performance, and longevity, our material handling equipment is built to meet the rigorous demands of industrial environments across the United States and Europe.
Engineered for Performance and Reliability
Our cranes are designed in strict accordance with international standards, including ISO 4301 for crane classification and IEC 60204-32 for electrical equipment. We utilize high-grade steel and advanced manufacturing processes to ensure structural integrity and long-term durability, even under continuous heavy-load operation.
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We offer a full line of material handling solutions tailored to diverse industrial applications. From single-girder and double-girder overhead cranes to a variety of gantry crane configurations, our equipment is engineered for precise load control and operational efficiency.
| Crane Type | Typical Capacity Range | Common Applications |
|---|---|---|
| Single-Girder Overhead Crane | 1 – 20 short tons (0.9 – 18 metric tons) | Maintenance, light assembly, machine shops |
| Double-Girder Overhead Crane | 5 – 100 short tons (4.5 – 90 metric tons) | Heavy fabrication, steel mills, power plants |
| Gantry Crane (Full & Semi) | 3 – 150 short tons (2.7 – 136 metric tons) | Yard handling, precast concrete, shipping yards |
Advanced Hoist Technology
Our electric wire rope hoists feature low-headroom designs, precision braking systems, and variable-frequency drive (VFD) options for smooth, controlled load positioning. Available with explosion-proof configurations for hazardous environments, our hoists are built for safety and minimal maintenance.
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Every lifting operation is unique. We provide end-to-end customization—from span and lift height to specialized end effectors and automation interfaces. Our global service network ensures quick response times, spare parts availability, and on-site technical support to maximize your uptime.
Frequently Asked Questions
Q: What is the typical lead time for a custom overhead crane?
A: Lead time varies based on configuration and capacity, but standard custom cranes typically ship within 8 to 12 weeks from engineering approval.
Q: Do you provide installation and commissioning services?
A: Yes, our trained technicians can handle complete installation, testing, and operator training on-site, or we can supervise your own rigging crew.
Q: Can your cranes be integrated with existing plant control systems?
A: Absolutely. We offer compatible control interfaces, including remote radio controls, pendant stations, and fully automated PLC-based systems.
Q: What safety features are included as standard?
A: Standard safety equipment includes overload protection, emergency stop, limit switches for hoist and trolley travel, and anti-sway control on request. Explosion-proof and other specialized options are available.
Q: What is your warranty policy?
A: We offer a comprehensive 24-month warranty on all crane components, covering defects in materials and workmanship, with extended service agreements available.
Contact Kelude for Your Lifting Needs
A: Ready to enhance your material handling efficiency? Contact our engineering team today for a detailed proposal and technical consultation. We are committed to providing safe, reliable, and cost-effective crane solutions tailored to your exact specifications.
| Brake Type | Braking torque | Brake Clearance | safety requirements |
|---|---|---|---|
| Shoe brake | Bydesign value | 0.5-1.0mm/Side | Brake Spring Parallel Double Brake Shoes |
| Disc Brake | Bydesign value | 0.3-0.6mm/Side | Multi-Spring Pressurization+Wear Compensation |
| Band brake | Bydesign value | 0.3-0.5mm | Emergencymanual release mechanism |
| Cone brake | Bydesign value | 0.2-0.4mm | Taper Radial Clearance Compensation |
