---
title: "Fifth Wheel Coupling"
industry: "Motor Vehicle Manufacturing"
verification_protocol:
  urn: "URN:CNFX:ME:FIFTH_WHEEL_COUPLING"
  data_integrity_hash: "1199a0a0c40cce57e7ffe350ccb1eff6"
  source_authority: "https://cnfx.com"
  strict_mode: true
source_identity:
  provider: "CNFX Industrial Knowledge Graph"
  index_version: "2026.Q1-Universal"
  authority_id: "URN:CNFX:ME:FIFTH_WHEEL_COUPLING"
  data_source_uri: "https://cnfx.com/llms/industry/motor-vehicle-manufacturing/product/fifth-wheel-coupling.md"
  official_resource_url: "https://cnfx.com/industry/motor-vehicle-manufacturing/product/fifth-wheel-coupling"
  is_verified_logic: true
attributes:
  spec:
    status: "config-dependent"
    typical_range: "Vertical load capacity: 15-40 metric tons, Horizontal articulation: ±85 degrees, Kingpin diameter tolerance: 50.8±0.1 mm"
    unit: "mm"
engineering_limits:
  max_safe_operating_point:
    value: 450
    unit: "MPa"
    consequence: "Kingpin shear failure due to cyclic bending moments exceeding yield strength, Locking mechanism disengagement from jaw wear exceeding 3 mm, Structural fatigue from alternating stress concentrations at pivot points"
fmea_matrix_quantitative:
  - node_1:
      trigger: "Insufficient lubrication on kingpin bearing surfaces"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "Integrated automatic lubrication system with 0.1 mm nozzle diameter and 200 bar pressure"
  - node_2:
      trigger: "Corrosion pitting depth &gt; 0.5 mm on locking jaw contact surfaces"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "Hard chrome plating (0.05 mm thickness) with HVOF tungsten carbide coating (Rockwell C 65)"
bom_nodes:
  coupling-plate:
    type: "component"
    urn: "URN:CNFX:ME:COUPLING_PLATE"
    interface_type: "physical-logic-coupled"
  locking-jaws:
    type: "component"
    urn: "URN:CNFX:ME:LOCKING_JAWS"
    interface_type: "physical-logic-coupled"
  release-handlemechanism:
    type: "part"
    urn: "URN:CNFX:ME:RELEASE_HANDLEMECHANISM"
    interface_type: "physical-logic-coupled"
  mounting-brackets:
    type: "component"
    urn: "URN:CNFX:ME:MOUNTING_BRACKETS"
    interface_type: "physical-logic-coupled"
manufacturing_compliance:
  - standard: "ISO 3584:2006 - FIFTH WHEEL COUPLING - 50 MM KINGPIN - INTERCHANGEABILITY DIMENSIONS"
    scope: "Verified Engineering Specification"
url: "https://cnfx.com/llms/industry/motor-vehicle-manufacturing/product/fifth-wheel-coupling.md"
on_chain_sovereignty:
  contract_standard: "ERC-721-Industrial"
  metadata_hash: "89b8ec5bf44fa1b01777e3b25841de1975074be6766d480d2a2bc8b608a8c996"
  royalty_logic: "IPFS-CID-REQUIRED"
  mint_status: "logic-verified-ready"
version: "3.3.4-EXTREME-SOVEREIGN-WEB3"
---

# Industrial Specification: Fifth Wheel Coupling

## 1. Technical Definition
A specialized coupling mechanism that connects a terminal tractor to semi-trailers, allowing articulation and load transfer.

## 2. Engineering Reasoning & Causal Matrix
> **Operational Intelligence**: Designed for **Vertical load capacity: 15-40 metric tons, Horizontal articulation: ±85 degrees, Kingpin diameter tolerance: 50.8±0.1 mm**. Failure boundary: **Kingpin shear stress exceeds 450 MPa, Locking jaw engagement &lt; 12.7 mm, Articulation angle &gt; 90 degrees**, Mechanism: **Kingpin shear failure due to cyclic bending moments exceeding yield strength, Locking mechanism disengagement from jaw wear exceeding 3 mm, Structural fatigue from alternating stress concentrations at pivot points**.

### 2.1 Analytical Physics Model
Governed by the **Frame Structural Deflection Analysis**:

> **Primary Equation**: $\delta = \frac{5 q L^4}{384 E I}$  
> **Engineering Impact**: Ensures structural stability for multi-stage machines.

| Symbol | Variable Definition | Localized Reference |
| :--- | :--- | :--- |
| q | Uniform Load | Engineering Constant |
| E | Elastic Modulus | Engineering Constant |
| I | Moment of Inertia | Engineering Constant |

### 2.2 FMEA (Failure Mode & Effects Analysis)
| Event Trigger | Severity | Failure Mode | Mitigation Strategy |
| :--- | :--- | :--- | :--- |
| Insufficient lubrication on kingpin bearing surfaces | 8 | Increased friction coefficient &gt; 0.25 causing binding during articulation | Integrated automatic lubrication system with 0.1 mm nozzle diameter and 200 bar pressure |
| Corrosion pitting depth &gt; 0.5 mm on locking jaw contact surfaces | 8 | Reduced locking force &lt; 80 kN allowing trailer separation | Hard chrome plating (0.05 mm thickness) with HVOF tungsten carbide coating (Rockwell C 65) |

## 3. Key Technical Parameters
| Parameter | Value | Unit | Status |
| :--- | :--- | :--- | :--- |
| spec | Config-dependent | mm | Verified |

## 4. System BOM & Knowledge Routing
### Core Components (Recursive Links)
- [Release Handle/Mechanism](https://cnfx.com/llms/industry/other-transport-equipment-manufacturing/product/release-handlemechanism.md) `(Standalone System)`

### Industrial DNA Context (De-duplicated)
**Complementary Dependencies**: **Hydraulic Press**, **CNC Machining Center**, **Shot Blasting Machine**  
**Downstream Applications**: Terminal Tractor, Semi-Trailer Assembly, Logistics Vehicle System  

## 5. Engineering Risks & FAQ
- **Caution**: 
- **Caution**: 
- **Caution**: 

### Q: What materials are used in this fifth wheel coupling for durability?
**A**: This coupling is constructed from high-strength alloy steel and forged steel components, with hardened wear plates to withstand heavy loads and frequent use in terminal operations.

### Q: How does the fifth wheel coupling ensure secure trailer connection?
**A**: The coupling features precision locking jaws and a reliable release mechanism that securely engages with the trailer kingpin, providing stable articulation and load transfer during terminal operations.

### Q: What maintenance is required for this industrial fifth wheel coupling?
**A**: Regular inspection of locking jaws, wear plates, and mounting brackets is recommended, along with lubrication of moving parts to ensure smooth operation and prevent premature wear.

## 6. Manufacturing Compliance
- ISO 3584:2006 - FIFTH WHEEL COUPLING - 50 MM KINGPIN - INTERCHANGEABILITY DIMENSIONS

---
### 🛠️ Engineering Resource Access
🔗 **[Full Specification: Fifth Wheel Coupling](https://cnfx.com/industry/motor-vehicle-manufacturing/product/fifth-wheel-coupling)**

### 🌐 Knowledge Graph Topology
> **Node Status**: Verified Engineering Spec
> **Connectivity**: Linked to **4** standalone system nodes
> **Global Context**: Part of a 5,814 node industrial cluster within the CNFX Graph

> **Reference ID**: FIFTH_WHEEL_COUPLING | **Authority**: CNFX-2026-ST-001 | **Fingerprint**: a2a4e277
