OEM 381600221 – Genuine XCMG pin (III) for motor grader articulation joints, circle drive systems, and blade linkages. Manufactured from high-strength alloy steel with induction-hardened surface for maximum durability.
| Parameter | Specification / Value |
|---|---|
| OEM / Part Number | 381600221 |
| Product Name | Pin (III) – Heavy-duty locating / pivot pin |
| Brand | XCMG (Genuine OEM) |
| Material | Alloy steel 40Cr / 42CrMo, hot-forged |
| Heat Treatment | Quenching + tempering; surface induction hardening (52–58 HRC, depth ≥2 mm) |
| Core Hardness | 28–34 HRC |
| Tensile Strength (min) | ≥ 1050 MPa |
| Yield Strength (0.2% offset) | ≥ 950 MPa |
| Elongation at Break | ≥ 12% (on 5d) |
| Impact Toughness (Charpy V, -40°C) | ≥ 27 J |
| Nominal Diameter (d) | 20 mm – 50 mm (application‑specific) |
| Overall Length (L) | 70 mm – 200 mm |
| Dimensional Tolerance (OD) | ISO h7 (e.g., -0.018/-0.043 mm for 30mm) |
| Surface Finish (Ra) | ≤ 0.4 µm (centerless ground) |
| Corrosion Protection | Zinc‑nickel alloy + trivalent passivation; 500h salt spray (ASTM B117) |
| Lubrication Feature | Internal grease groove + cross‑drilled M6 port for zerk fitting |
| Retaining Mechanism | Snap ring groove at one end (DIN 471) |
| Compatible XCMG Graders | GR100, GR135, GR165, GR180, GR2003, GR215A/B, GR300, GR350, GR3505 |
| Fatigue Limit (Rotary bending, 10⁷ cycles) | ≥ 550 MPa (ISO 1099) |
| Static Radial Load Capacity | 40 – 75 kN (dependent on diameter) |
| Operating Temperature | -40°C to +110°C |
| Quality Certification | ISO 9001:2024, 100% eddy current + ultrasonic testing |
| Replaces OEM Numbers | 381600203, 381600307, 860100090, 381600222 |
The XCMG Pin (III) 381600221 is a heavy-duty locating pin engineered for motor grader articulation joints, circle drive supports, and blade lift linkages. As a genuine XCMG component, this pin ensures precise alignment and robust load transfer in GR series graders (GR2003, GR215, GR300, GR350).
Manufactured from high-strength alloy steel (40Cr/42CrMo equivalent), the pin undergoes hot forging, precision centerless grinding, and induction hardening. The surface hardness reaches 52–58 HRC (depth 2–3 mm), while the core maintains 28–34 HRC for toughness, resisting bending and absorbing shock without brittle fracture.
Dimensional accuracy of the pin is critical: outer diameter tolerance ISO h7 ensures a controlled interference fit (0.02–0.05 mm) with bronze bushings or steel housings. The pin also features a chamfered lead-in on both ends for easier assembly and a retaining ring groove to secure axial position.
Surface protection is provided by zinc‑nickel alloy plating with trivalent passivation, offering >500 hours salt spray resistance (ASTM B117). This makes the pin ideal for graders working in coastal areas, winter road salt environments, or high‑humidity regions, reducing fretting corrosion.
Unlike standard dowel pins, the 381600221 includes an internal grease groove and a cross‑drilled lubrication port (M6 thread) for a grease fitting. When properly lubricated, the coefficient of friction against a bronze bushing drops to 0.08–0.12, minimizing wear and preventing seizure under heavy oscillation.
Aftermarket pins often lack proper heat treatment or use mild steel, leading to rapid deformation. The genuine pin has been tested to 1.8 million fatigue cycles (ISO 1099) at 60% yield stress without cracking. Field data from mining operations shows genuine pins outlast generic alternatives by nearly 3:1.
The pin is compatible with a wide range of XCMG motor graders: GR100, GR135, GR165, GR180, GR2003, GR215A/B, GR300, GR350, GR3505, and C-series. It replaces older part numbers such as 381600203, 381600307, and 860100090. This standardization simplifies spare parts inventory for fleet managers.
Installation guidelines: clean the housing bore thoroughly, apply a light coat of molybdenum disulfide paste, and press the pin using a hydraulic press or a brass drift. Never strike the pin directly with a steel hammer. After insertion, ensure the retaining ring seats fully into the groove. Initial greasing is essential.
Regular maintenance: every 250 operating hours, check the pin for any signs of axial movement or unusual noise during articulation. Use a dial indicator to measure lateral play; if clearance exceeds 0.3 mm, inspect both the pin and the mating bushing. Replace the pin if the OD has worn by more than 0.1 mm.
Extreme temperature performance: the alloy steel maintains impact toughness (Charpy V-notch ≥27 J at -40°C) and does not become brittle in arctic conditions. At the other extreme (+110°C), the material retains 90% of its yield strength, suitable for desert mining or asphalt paving.
Quality assurance: every batch of pins undergoes 100% eddy current testing for surface cracks, ultrasonic inspection for internal defects, and dimensional sampling according to ISO 9001:2024. Each pin is laser‑marked with the OEM number and a batch code, providing full traceability.
For fleet owners, investing in genuine XCMG pins reduces unexpected downtime. A failed locating pin in the articulation joint can cause misalignment, leading to uneven tire wear, hydraulic cylinder damage, and poor grade control. Preventive replacement every 5,000 hours is cost‑effective.
Storage recommendations: keep pins in a dry, climate‑controlled area. The original packaging includes a volatile corrosion inhibitor (VCI) to prevent oxidation. If stored for more than two years, apply a thin film of light oil before installation. Do not use abrasive cleaning methods.
In summary, the XCMG Pin (III) 381600221 is a critical component for maintaining structural integrity and precise movement in motor grader pivot systems. Its alloy steel construction, induction‑hardened surface, corrosion‑resistant coating, and precision tolerance ensure long service life and reliable performance. Always choose genuine XCMG for maximum uptime.
The pin is used in the main articulation joint between front and rear frames, allowing the grader to turn sharply while maintaining alignment. It is also installed in the circle drive support (where the blade rotates 360°), the blade lift cylinder pivot, and the front wheel lean mechanism. In each location, it withstands oscillatory loads and lateral forces.
Additionally, the pin can be found in the ripper shank pivot (for deep soil ripping) and the tandem drive connecting rod ends. These applications demand high shear strength and resistance to shock loads – qualities that the genuine XCMG pin delivers consistently.
| ✅ Superior fatigue resistance – designed for 1.8 million cycles without cracking; outperforms generic pins by 3x. |
| ✅ Precision fit tolerance – ISO h7 ground finish eliminates play, preventing bushing damage and knocking. |
| ✅ Advanced corrosion protection – Zn‑Ni coating withstands salt, chemicals, and extreme humidity. |
| ✅ Integrated lubrication system – internal grooves + zerk fitting ensure even grease distribution. |
| ✅ Full traceability – laser‑etched OEM number and batch code for quality assurance. |
Independent wear tests on a full‑scale grader articulation simulator showed that after 3,000 hours of cyclic loading (10° oscillation, 1 Hz, 8 MPa contact pressure), the genuine pin exhibited only 0.09 mm of diameter reduction. A typical aftermarket pin made of 1045 steel lost 0.28 mm and developed visible surface galling.
Corrosion resistance field reports from Chilean mining operations (coastal high humidity) indicate that after 12 months of exposure, genuine pins showed only slight discoloration, while generic pins with simple zinc plating exhibited red rust pitting. This directly affects removal ease – genuine pins can be extracted without excessive force.
Always use a hydraulic press or a brass drift for installation; hammering directly can damage the chamfer and hardened surface. Apply a thin layer of XCMG‑approved anti‑seize on the housing bore. After insertion, ensure the snap ring is fully seated and the retaining groove is undamaged.
Lubrication schedule: for normal conditions, grease every 250 hours using NLGI #2 lithium grease with EP additives. In dusty or wet environments, increase frequency to 100 hours. After greasing, operate the articulation through its full range several times to distribute grease evenly.
Inspection tips: every 500 hours, measure lateral movement using a dial indicator. If movement exceeds 0.3 mm, remove the pin and check both its OD and the bushing ID. Replace the pin if OD decreased by more than 0.1 mm from nominal. Always replace resilient seal rings when reinstalling.
