Sany Boom

The Sany Boom is the primary load‑bearing working arm of Sany heavy truck cranes, all‑terrain cranes, and large excavators, supporting all lifting and digging forces.

This Sany Boom integrates a high-strength multi‑section telescoping structure, a telescoping mechanism, a boom cylinder, locking pins, bumper blocks, and adjusting pillows into a single factory‑matched assembly. When you need authentic replacement components, trust Sany Parts to deliver factory-original quality and precise fitment.

The Sany Boom is specifically designed for Sany STC‑series and SAC‑series truck cranes, featuring a high-strength steel structure with U‑shaped or octagonal cross-sections that distribute loads efficiently while minimizing dead weight and maximizing reach.

Sany Boom — OEM telescoping boom assembly for Sany heavy truck cranes and construction equipment

What is the Sany Boom?

The Sany Boom is a complete OEM telescoping structural assembly engineered to support the lifting and material‑handling functions of Sany heavy truck cranes, all‑terrain cranes, and large excavators. This multi‑section telescoping arm forms the working envelope of the machine, carrying the load from the hook or bucket through the boom structure into the rotating chassis.

The Sany Boom comprises 13 precision‑engineered components that function as an integrated structural and actuation system. The main telescoping boom sections (jib) are fabricated from high‑strength steel plate using a multi‑folded forming process, creating U‑shaped or octagonal cross‑sections that provide excellent buckling resistance. A telescoping mechanism and a dedicated telescoping cylinder generate the extension and retraction forces that allow the boom to change length. Locking pins secure each boom section at the desired extension point, while a luffing balance valve controls the raising and lowering of the boom.

The Sany Boom is designed with a single‑cylinder pin‑operated telescoping system on many high‑capacity truck cranes. The internal mechanism uses extension and retraction cables working in conjunction with hydraulic cylinders to ensure that all boom sections extend and retract smoothly and synchronously. Holding valves integrated into the cylinder circuits lock the boom at any length, preventing unintended movement even if hydraulic pressure is lost.

The Sany Boom is a direct replacement for worn or damaged boom assemblies on Sany STC‑series and SAC‑series truck cranes. By using this genuine assembly, you ensure that boom section curvature, inter‑section clearance, and hydraulic synchronization match factory specifications, eliminating the unpredictable bending and binding commonly associated with mismatched aftermarket components.

Product Parameters of Sany Boom

Technical specifications: The Sany Boom is engineered for multi‑section telescoping operation, typically offering configurations from 4 to 7 sections depending on the crane model. The boom structure is fabricated from fine‑grain high‑strength steel plate (minimum yield strength up to 890 MPa), formed into U‑shaped or octagonal cross‑sections that provide superior buckling resistance while minimizing weight. The telescoping mechanism is a single‑cylinder pin‑operated system or cable‑synchronized multi‑cylinder arrangement, depending on the crane series and capacity rating.

All components of the Sany Boom are manufactured under ISO 9001:2025 certification and are 100% traceable to original production batches. The Sany Boom has been validated on Sany STC and SAC series cranes operating globally, demonstrating a field service life exceeding 10,000 operating hours under heavy‑duty conditions when properly maintained.

Why Choose Our Sany Boom?

Complete 13‑Component OEM Kit — Precisely Matched Sections: The Sany Boom includes every structural and actuation component as a single, factory‑matched assembly. This eliminates the geometric incompatibilities that arise from sourcing individual boom sections from different suppliers. The multi‑folded high‑strength steel plate forming process ensures consistent wall thickness and section curvature across all sections, guaranteeing that inter‑section clearances are within factory specifications for smooth, binding‑free telescoping operation.

High‑Strength Steel Construction for Maximum Lifting Capacity: The Sany Boom is fabricated from fine‑grain high‑strength steel plate with U‑shaped or octagonal cross‑sections that provide excellent buckling resistance while keeping the boom lightweight. This design approach maximizes the crane’s lifting capacity chart while reducing overall machine weight, contributing to greater payload capacity and more efficient transport. The boom incorporates maintenance‑free composite wear pads between telescoping sections, reducing friction and eliminating the need for periodic grease application on sliding surfaces.

Precision Synchronized Telescoping with Holding Valves: The Sany Boom uses a single‑cylinder pin‑operated telescoping system or cable‑synchronized multi‑cylinder arrangement depending on the crane capacity. The telescoping mechanism (10649855) ensures that all boom sections extend and retract simultaneously without jerking or lag. Holding valves integrated into the telescoping cylinder (10047105) lock the boom at any length, preventing unintended retraction even if hydraulic pressure is lost. This is a critical safety feature for maintaining load position during extended lifting operations.

Fleet‑Proven Reliability and Comprehensive Warranty: The Sany Boom is standard equipment on Sany STC‑series truck cranes and SAC‑series all‑terrain cranes in over 100 countries. Fleet data shows that genuine Sany boom assemblies deliver an average service life exceeding 10,000 operating hours—three times longer than generic aftermarket assemblies—while eliminating boom section binding and hydraulic synchronization failures. The assembly is backed by a 24‑month manufacturer’s warranty covering structural cracks, telescoping mechanism failure, and cylinder leakage.

What are the Routine Maintenance Considerations for the Sany Boom?

Daily visual inspection before operation: Inspect the Sany Boom for visible damage to boom sections, including dents, cracks, or deformation. Check all visible welds for signs of cracking or separation. Examine telescoping mechanism cables (if equipped) for fraying, stretching, or overtightening. Verify that all locking pins (A210501000039) are fully engaged and that no pin has backed out. Listen for abnormal noises during boom operation—grinding may indicate worn wear pads, while squealing may indicate insufficient lubrication on sliding surfaces.

Lubrication of telescoping sections and pivot pins — every 250 operating hours: For boom designs that do not use composite wear pads, lubricate all sides of the telescoping boom sections with the recommended EP‑3MG grease. Apply grease to the boom pivot pins, the luffing cylinder pins, and the telescoping cylinder mounting pins. If the machine is equipped with a central lubrication system, ensure that the grease reservoir is filled and that all lubrication lines are clear.

Telescoping function test and wear pad inspection — every 500 operating hours: Extend and retract the Sany Boom through its full range of motion while observing extension and retraction speeds. Any section that extends or retracts more slowly than others indicates a synchronization issue or internal cable problem. Inspect the bumper blocks (10041332) at the end of each boom section for wear or cracking—replace any block that shows significant deformation. Check that the adjusting pillows (10041333, 10041336) are properly torqued.

Preventative overhaul and NDT inspection — every 4,000 hours or 2 years: For high‑use cranes, Sany recommends a full structural inspection of the Sany Boom every 4,000 operating hours. Perform magnetic particle or dye penetrant inspection on all boom section welds and high‑stress areas to detect fatigue cracks that are not visible to the naked eye. Replace the telescoping cylinder seal kit, inspect the telescoping mechanism cables for elongation, and replace the composite wear pads. Inspect the jib (10667459) mounting pins and bushings for wear beyond 0.5 mm. By following this proactive schedule, the Sany Boom can reliably exceed 10,000 operating hours.

The telescoping cylinder assembly (10047105) is the hydraulic actuator that generates the extension and retraction forces of the Sany Boom. This cylinder is a double‑acting unit equipped with integral holding valves that lock the boom at any length, preventing unintended retraction under load. The cylinder is manufactured from high‑strength steel tube with a honed internal finish and a hard‑chrome‑plated piston rod. The piston rod is induction‑hardened to a depth of 1.5 mm with a surface hardness of HRC 55‑60, providing exceptional wear resistance. If the telescoping cylinder leaks externally or fails to hold position, rebuild the cylinder using a genuine Sany seal kit and replace the rod if scoring exceeds 0.2 mm.

The telescoping mechanism (10649855) on the Sany Boom uses either a single‑cylinder pin‑operated arrangement or a cable‑synchronized multi‑cylinder system. In the single‑cylinder configuration, a single telescoping cylinder sequentially extends and retracts each boom section using a pin locking mechanism. In the cable‑synchronized system, all sections move simultaneously using a master‑slave cylinder arrangement linked by extension and retraction cables. The cables must be inspected monthly for stretching, fraying, or overtightening. If a cable fails, the affected boom sections may extend or retract unevenly, potentially causing structural damage.

The bumper blocks (10041332) are located at the end of each boom section and serve as cushioning elements when the boom reaches full extension. These blocks prevent metal‑to‑metal contact between sections and absorb the impact energy at the end of stroke. If a bumper block is missing or worn beyond 3 mm of original thickness, the telescoping cylinder may bottom out internally, potentially damaging the cylinder cushion and piston assembly. Replace bumper blocks as a set whenever any single block shows significant wear.

For Sany truck cranes operating in extreme cold climates (below -25°C), special considerations apply to the Sany Boom. Use low‑viscosity hydraulic fluid (L‑HV22 or L‑HV32) in the telescoping circuit to ensure adequate flow during cold starts. The telescoping cylinder may extend more slowly until the fluid warms; cycle the boom slowly 3‑4 times before full operation. The composite wear pads retain their low‑friction properties down to -40°C, but steel sections contract slightly in cold conditions. Do not force the boom to extend if resistance is excessive—wait for the hydraulic fluid to warm before retesting.

The Sany Boom is also available as part of a complete boom system overhaul kit, which includes all boom sections, the telescoping cylinder, the telescoping mechanism, all locking pins, bumper blocks, adjusting pillows, and the jib assembly. Sany recommends this complete‑kit approach for vehicles with over 8,000 operating hours, as it allows the entire boom system to be renewed in a single service event, eliminating the risk of hidden fatigue cracks or internal cable damage that could lead to catastrophic failure. Contact our parts specialists through the Get Quotation button above for custom kit configurations.