B Series Short-Pitch Double-Row Chain

The B series short-pitch double-row chain is a standardized heavy-duty transmission chain that complies with ANSI (American National Standards Institute), ISO international standards, and the national standard GB/T 1243. Its core positioning is a high-strength power transmission component for medium-high speed and medium-heavy load scenarios. With the advantages of compact structure, strong load-bearing capacity, and stable transmission, it is widely used in various mechanical transmission systems that require higher tensile strength and torque, and is an important transmission part in industrial production.

I. Basic Structure and Core Definition

The B series short-pitch double-row chain belongs to the short-pitch precision transmission chain. “Short-pitch” refers to the relatively compact distance (pitch) between the centers of two adjacent pins, which is suitable for small-size sprockets and provides better transmission stability. “Double-row” means the chain contains two parallel rows of inner and outer chain links, which share a set of pins and outer chain plates, with a more stable structure and stronger load-bearing capacity than single-row chains, suitable for transmission scenarios with large load, high torque and limited installation space.

Its core structure consists of six major components: inner chain plates, outer chain plates, pins, bushings, rollers, and spacing sleeves. All components work together: the rollers are sleeved on the outside of the bushings to reduce friction with the sprocket teeth; the bushings are fixed to the inner chain plates, and the pins pass through the bushings and spacing sleeves (used to separate the two rows of inner chain links) to connect with the outer chain plates, forming flexibly rotatable double-row chain links. The overall structure is compact and reasonable, ensuring high transmission efficiency, strong load-bearing capacity and convenient maintenance.

Compared with the A series double-row chain, the B series double-row chain has slightly smaller chain plate thickness and pin diameter, and the pitch is consistent with the corresponding model of the A series (e.g., both 10B-2 and 10A-2 have a pitch of 15.875mm). It is compatible with the corresponding specification of B series double-row sprockets, has strong interchangeability, and can be flexibly selected according to the equipment design requirements and load conditions.

II. Core Features

• Compact Structure, Strong Load-Bearing Capacity: The double-row parallel design effectively increases the contact area with the sprocket and the overall tensile strength of the chain. Its ultimate tensile load is about 1.9 times that of the same-model single-row chain, which can stably bear medium-heavy loads and large torques;
• High Standardization and Versatility: Following unified international standards, B series short-pitch double-row chains of the same model produced by different manufacturers are interchangeable. They are compatible with standard B series double-row sprockets, facilitating procurement, replacement and maintenance;
• Stable Transmission, Low Vibration: The short-pitch design reduces chain jitter during operation, and the double-row symmetric structure ensures uniform force distribution, effectively reducing transmission vibration and noise, suitable for scenarios with high requirements for operation stability and precision;
• Good Cost Performance and Practicality: Compared with multi-row chains (three-row or four-row), it has a more compact structure, lower cost and more convenient maintenance; compared with single-row chains, it has stronger load-bearing capacity, which can balance load-bearing requirements and economic benefits;
• Wide Application Range: Suitable for medium-high speed and medium-heavy load transmission, it can work stably in normal temperature, dry or slightly dusty environments without complex protective devices, and is compatible with various heavy-duty general machinery.

III Material and Technology

• Common Materials: 40Cr, 40Mn2 and 45# carbon steel are selected for conventional scenarios, which have high strength, wear resistance and toughness to meet medium-heavy load needs; SUS304, SUS316 stainless steel can be selected for special scenarios (such as mild corrosion, high hygiene requirements) to improve corrosion resistance;
• Heat Treatment Process: Pins, bushings, and rollers are subjected to quenching + tempering treatment to improve hardness and wear resistance and extend service life; inner and outer chain plates are subjected to quenching and tempering treatment to ensure the toughness and tensile strength of the chain and avoid chain breakage during heavy-load transmission;
• Surface Treatment: Black oxide (blueing) treatment is usually adopted to play a role in rust and corrosion prevention, suitable for ordinary industrial environments; galvanizing and nickel plating can also be selected according to requirements to improve rust resistance and appearance texture.

IV. Typical Application Scenarios

Due to its compact structure, strong load-bearing capacity and stable transmission, the B series short-pitch double-row chain is widely used in power transmission of various heavy-duty general machinery. Common scenarios include:

• General Heavy-Duty Machinery: Power transmission of reducers, large blowers, water pumps, conveyors, elevators, crushers and other equipment;
• Light Industry Heavy-Duty Machinery: Heavy-duty packaging machinery, printing machinery, textile machinery, food processing machinery (stainless steel material is suitable for corrosive scenarios);
• Agricultural and Construction Machinery: Transmission systems of medium-sized agricultural machinery (such as harvesters, threshers), small construction machinery, suitable for heavy-load working needs in complex environments;
• Other Scenarios: Power transmission of small and medium-sized machine tools, warehousing and logistics equipment, mining auxiliary equipment, and various customized transmission equipment with medium-high speed and medium-heavy load.

V. Selection and Usage Notes

Selection Points: Select the corresponding chain number according to the working load, speed and installation space of the equipment, ensuring that the ultimate tensile load of the chain is 1.2-1.5 times greater than the actual working load; the pitch selection should match the sprocket pitch to avoid transmission jamming and