The 805639792 Cotter Pin (Split Pin) is a genuine OEM fastening component manufactured to GB/T91-2000 standard for XCMG motor graders and heavy construction equipment. This precision‑formed pin provides reliable mechanical locking for castellated nuts, clevis pins, and shaft assemblies on XCMG GR series graders.
Engineered from high‑quality spring steel with a Dacromet (zinc‑flame coating) finish, the 805639792 cotter pin offers exceptional corrosion resistance and eliminates the risk of hydrogen embrittlement. It directly replaces worn, corroded, or missing cotter pins in blade circle linkages, wheel hub assemblies, and hydraulic cylinder mounts.
Each pin features a 1.6 mm nominal diameter, 16 mm overall length, and a split‑leg design that locks into place when spread. The Dacromet coating provides over 500 hours of salt spray resistance, ensuring long‑term reliability in harsh environments.
| Parameter | Specification |
|---|---|
| OEM Number | 805639792 |
| Brand | XCMG (Genuine Original Equipment) |
| Standard | GB/T91-2000 ( ISO 1234:1997) |
| Product Type | Cotter Pin / Split Pin |
| Nominal Diameter (d) | 1.6 mm |
| Length (L) | 16 mm (±0.25 mm) |
| Maximum Diameter (d max) | 1.8 mm |
| Head Width (a) | 3.2 – 3.6 mm |
| Head Height (c) | 4.0 mm (nominal) |
| Leg Length Difference | 1.25 – 2.50 mm |
| Material | High‑carbon spring steel (65Mn equivalent) |
| Hardness | 450 – 550 HV |
| Surface Finish | Dacromet (Zinc‑Flake Coating) |
| Coating Thickness | 5 – 12 μm |
| Salt Spray Resistance | 500+ hours (ASTM B117 / GB/T 10125) |
| Hydrogen Embrittlement | None (Dacromet is a non‑electrolytic process) |
| Operating Temperature | -40°C to +150°C |
| Weight (each) | ≈ 0.5 g |
| Compatible Models | XCMG GR135, GR165, GR180, GR215, GR260, GR300, GR350 motor graders |
| Superseded Part Numbers | 805639701, 805639712, 805639775 |
| Certifications | ISO 9001:2015, IATF 16949, RoHS |
The XCMG 805639792 Cotter Pin is a small but essential fastening component that prevents nuts and pins from loosening under vibration. When inserted through a castellated nut or clevis pin hole, the split legs are bent outward, creating a positive mechanical lock that cannot be undone by vibration alone. This is critical for wheel hubs, blade circle bearings, and hydraulic cylinder attachments on motor graders.
Without a properly installed cotter pin, a castellated nut can back off, leading to bearing failure, wheel separation, or loss of blade control. The 805639792 is designed to be used once – after removal, it must be replaced with a new pin to ensure proper locking force and fatigue resistance.
The split‑leg design allows the pin to spring back slightly after bending, maintaining constant pressure against the nut slot. The 1.6 mm diameter is sized for M12 to M16 castellated nuts commonly found on XCMG grader axles and pivot pins.
The 805639792 features a Dacromet (zinc‑flame) coating, a non‑electrolytic zinc‑aluminum flake coating that provides exceptional corrosion resistance. Unlike traditional zinc plating, Dacromet does not cause hydrogen embrittlement, a critical advantage for spring steel components that rely on ductility to function properly. Dacromet is also known as zinc‑chromium coating, zinc‑flake coating, or by the trade names Dacromet, Dacrotized, or Geomet.
The coating consists of overlapping zinc and aluminum flakes bonded by a chromate binder, creating a labyrinth barrier that blocks corrosion pathways. Dacromet‑treated components achieve 500+ hours of neutral salt spray resistance per ASTM B117 (≈100 hours per micron of coating thickness). This makes the 805639792 ideal for graders operating in coastal areas, winter road salt environments, and mining applications where corrosion is a constant threat.
The coating thickness is typically 5‑12 μm, and the process is environmentally friendly compared to traditional electroplating, as it produces no acidic or alkaline wastewater. Dacromet also provides excellent resistance to high temperatures (up to 300°C) and retains its protective properties even after mechanical deformation of the pin legs.
To install a cotter pin, first torque the castellated nut to specification. Align the nut slots with the hole in the bolt or shaft. Insert the 805639792 pin through the hole until the head contacts the nut. Using pliers, bend both legs back at approximately 60‑90 degrees, one leg over the nut, the other leg along the flat. Do not over‑bend; the legs should not be fully flattened.
Never reuse a cotter pin. Once removed, the legs have been work‑hardened and will not provide the same locking force if rebent. Always replace with a new genuine XCMG 805639792 pin. Inspect the pin for any signs of rust or cracking before installation.
When replacing a pin on critical assemblies (wheel hubs, blade circle), use a torque wrench on the nut before installing the pin. After bending the pin legs, verify that the head sits flush against the nut. If the pin is too long, the legs may not bend cleanly; if too short, the head may not seat correctly. The 16 mm length is optimized for standard XCMG applications.
Aftermarket cotter pins are often made from low‑grade wire that cracks when bent, or have inconsistent leg lengths that prevent proper locking. The genuine XCMG pin is manufactured from high‑carbon spring steel that meets the hardness requirements of GB/T91‑2000 (450‑550 HV). The pin will withstand repeated bending without cracking, as required by the standard.
Counterfeit pins may have a simple zinc plating that corrodes within months, or a bright zinc coating that offers only 48 hours of salt spray resistance. The Dacromet finish on the 805639792 provides over 500 hours of protection, 10 times longer than standard plating. Additionally, counterfeit pins may be undersized, allowing the nut to rotate past the pin.
XCMG provides a 12‑month warranty against manufacturing defects. Each pin is batch‑tested for hardness and coating thickness. This supersedes older numbers 805639701 and 805639712, with improved corrosion resistance and a more consistent head geometry.
Inspect cotter pins during routine maintenance. Common indicators of failure: rust or corrosion on the pin, cracks in the bend area, or legs that have become loose or broken. Also, if the nut can be rotated by hand, the pin has likely failed or was never properly installed.
Preventive replacement is recommended every 2,000 operating hours or whenever the nut is removed for bearing service. The cost of a genuine cotter pin is negligible compared to the cost of a lost wheel or a damaged bearing. Always keep a stock of 805639792 pins in your parts inventory.
When rebuilding wheel hubs or blade circle bearings, replace all cotter pins regardless of apparent condition. The cyclic loading and vibration of grader operation work‑hardens the legs, making them brittle over time.
The 805639792 Cotter Pin is stocked in XCMG regional warehouses in North America (Houston), Europe (Rotterdam), Middle East (Dubai), and Asia (Shanghai). Standard air freight delivers within 3‑7 business days worldwide. Expedited shipping (1‑2 days) is available for urgent repairs.
Bulk orders (100+ pins) receive volume discounts and can be shipped via sea freight. Each pin is individually packed in anti‑corrosion paper or supplied in bulk bags. For large fleets, consignment stock programs are available to ensure immediate availability.
Don’t let a missing or corroded cotter pin compromise safety. Order the genuine XCMG 805639792 Cotter Pin today and ensure every castellated nut remains locked, tight, and secure.
The 805639792 Cotter Pin may be the smallest component in your motor grader, but it plays an outsized role in safety and reliability. A properly installed, corrosion‑resistant cotter pin keeps nuts from backing off, bearings from failing, and wheels from coming loose. Keep spare pins in your service truck for every repair.
Upgrade your motor grader’s fastener security with the XCMG genuine cotter pin. Engineered for strength, ductility, and corrosion resistance – order now and experience the quality that keeps your grader safe and productive.
