For over two decades, Hebei Boao Rubber Technology Co., Ltd. (under the renowned premium brand "Jinao") has been at the absolute forefront of research, design, chemical laboratory verification, and mass production of heavy industrial transport components.
Established in 2004 and spanning a state-of-the-art facility over 30 acres in the boye county Rubber Industrial Park (Baoding, Hebei, China), we have pioneered system-level machinery components. Our manufacturing ecosystem integrates high-performance conveyor rollers, mechanical steel components, and high-precision drive parts. We have passed the international quality management system certification in one go, certifying our standard of engineering excellence.
Explore our rolling, forming, vulcanization, and chemical validation production lines. We guarantee structural integrity from raw carbon steel and premium rubber compounds to final finished products.
Utilizing high-grade carbon steels (C45, 40Cr) and alloy structures. Teeth profiles are subjected to high-frequency induction hardening (HRC 45–55) to a depth of up to 2.5mm, extending chain wear life under harsh loads by up to 250%.
Equipped with dual-shielded or double-sealed ball bearings (2RS/ZZ) packed with high-temperature, extreme-pressure synthetic greases. This prevents ingress of abrasive coal, cement dust, and moisture in open mining environments.
Every metric sprocket undergoes advanced CNC tooth generation to conform strictly with DIN 8187, ISO 606, and ANSI standards, ensuring smooth chain engagement, minimized vibration, and silent operational acoustics.
| ISO/DIN Chain Pitch | Teeth Configurations | Hardness Level (Tooth Area) | Bearing Type Integration | Applicable Industries |
|---|---|---|---|---|
| 08B (12.70 mm) | 15T, 16T, 17T, 18T, 21T | HRC 45 - 50 | 6201-2RS / 6203-2RS | Light Automation, Packing, General Assembly Lines |
| 10B (15.875 mm) | 13T, 15T, 17T, 19T | HRC 48 - 52 | 6203-2RS / 6204-2RS | Food processing, Agricultural sorting, Light Conveyors |
| 12B (19.05 mm) | 13T, 15T, 17T | HRC 48 - 54 | 6204-2RS / 6205-2RS | Cement mixing plants, Bulk baggage handling, Warehouses |
| 16B (25.40 mm) | 11T, 13T, 15T, 17T | HRC 50 - 55 | 6205-2RS / 6306-2RS | Heavy Mining, Metallurgy, Steel mill scrap conveyors |
Our commitment to quality goes beyond simple dimensional inspections. As a global industrial supplier, we run a specialized inspection and chemical analysis laboratory in-house to verify the microstructure of the alloys and polymers we use.
Our mechanical components and conveyor systems are widely integrated into massive industrial operations globally. Here are some of our major partners and long-term project cases:
Taihang Steel
Tsingshan Group
Zijin Mining
China Railway Group Mixing Plant
Conch Cement
Datong Coal Group
Our machining floor utilizes fully automated multi-axis machining centers that generate highly repeatable tooth contours on Metric Idler Sprockets. This minimizes localized friction zones, reduces system vibration, and keeps chain drives properly tensioned over long intervals.
Located in the heart of Northern China's industrial hub, we source raw materials directly from major domestic steel mills. This integration protects our international buyers from pricing spikes and guarantees lead times that outpace general trading agents.
Every single casting and forged piece is assigned a unique batch number, traceable back to the ladle analysis. We perform impact testing, ultrasonic crack detection, and hardness validation profiles to confirm that our parts can withstand severe shock loads without fracturing.
Consolidate your heavy industrial supply chain. Our factory delivers comprehensive conveyor solutions and drive maintenance plans from one centralized team.
Comprehensive planning, repair advice, scheduled maintenance, and emergency parts replacement programs designed to ensure your conveyor drives run smoothly and efficiently.
Supply of custom-machined metric sprockets, heavy-duty rollers, and premium conveyor belts. We support safety stock programs to ensure your facility maintains uninterrupted operational uptime.
We work to optimize drive system efficiency, decrease component wear rates, and deliver mutual, long-term commercial value to all our operating partners.
We actively benchmark our manufacturing and quality management workflows against major international standards. View our quality credentials below:
A metric idler sprocket is a non-driving, free-rotating sprocket containing an integrated bearing or bushing. It is installed along chain paths to guide, tension, and maintain proper wrap angles for chains. Unlike drive sprockets, which are keyed directly to motor shafts to transmit rotational torque, idlers rotate freely on fixed shafts to absorb slack and vibration.
Bulk materials (such as iron ore, coke, and cement) produce highly abrasive dust. Standard carbon steel teeth wear quickly under these conditions, leading to rapid tooth profile deformation and chain slippage. Induction hardening localized specifically on the teeth (HRC 48-55) provides a tough, wear-resistant outer shell while keeping the sprocket core ductile enough to handle shock loads without cracking.
Generally, a tensioning idler sprocket should have a minimum of 13 to 17 teeth. Using fewer teeth can cause polygon action, which introduces speed fluctuations and vibrations into the chain drive. A larger tooth count distributes structural load across more teeth, reducing localized wear on both the chain rollers and the sprocket profile.
For operations exposed to fine grit, such as mining and milling, 2RS double-lip synthetic rubber contact seals are recommended. These seals keep bearing grease inside the housing while preventing abrasive micro-particles from entering. In high-temperature applications, specialized Teflon or Viton seals are used along with high-temperature synthetic greases.
Key indicators include hooking of the sprocket teeth, checking if teeth have thinned by more than 10-15% of their original width, bearing noise, or axial play in the sprocket assembly. Regular preventative maintenance checks prevent damaged sprockets from causing accelerated wear or failure on the roller chain itself.
Yes. Utilizing our advanced CNC machining centers and chemical/physical verification testing facilities, we produce custom-engineered metric idler sprockets. We accommodate specific pitch requirements (ISO 08B through 32B), non-standard tooth profiles, custom bore sizes, and specialized carbon steel alloys based on your engineering drawings.
We are committed to providing you with the highest quality products and excellent services. If you have any questions or need assistance with our products, please feel free to contact us and we will be happy to assist you with technical calculations, material verification reports, and customized volume pricing.
Boao Rubber
