---
title: "Tool Joint"
industry: "Machinery and Equipment Manufacturing"
verification_protocol:
  urn: "URN:CNFX:ME:TOOL_JOINT"
  data_integrity_hash: "d9a79363a96918d6b76865e5729fca31"
  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:TOOL_JOINT"
  data_source_uri: "https://cnfx.com/llms/industry/machinery-and-equipment-manufacturing/product/tool-joint.md"
  official_resource_url: "https://cnfx.com/industry/machinery-and-equipment-manufacturing/product/tool-joint"
  is_verified_logic: true
attributes:
  spec:
    status: "config-dependent"
    typical_range: "70-210 MPa axial load, 35-105 MPa torsional stress, -40°C to 150°C temperature"
    unit: "mm"
engineering_limits:
  max_safe_operating_point:
    value: 550
    unit: "MPa"
    consequence: "High-cycle fatigue from cyclic loading exceeding 10^7 cycles at stress amplitudes &gt;275 MPa, thread galling due to frictional heat generation exceeding 250°C at contact surfaces, stress corrosion cracking in H2S environments above 0.05 psi partial pressure"
fmea_matrix_quantitative:
  - node_1:
      trigger: "Thread pitch deviation exceeding 0.025 mm per 25.4 mm due to manufacturing tolerance stack-up"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "Implement coordinate measuring machine verification with 0.005 mm accuracy for all thread profiles, apply DLC coating with 0.5 μm thickness on mating surfaces"
  - node_2:
      trigger: "Resonant vibration at 85-120 Hz matching drill string natural frequency"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "Integrate tuned mass damper with 15 kg mass and 0.3 damping ratio, enforce maximum surface roughness Ra 1.6 μm via shot peening"
bom_nodes:
  threaded-section:
    type: "component"
    urn: "URN:CNFX:ME:THREADED_SECTION"
    interface_type: "physical-logic-coupled"
  sealing-surface:
    type: "component"
    urn: "URN:CNFX:ME:SEALING_SURFACE"
    interface_type: "physical-logic-coupled"
  locking-mechanism:
    type: "part"
    urn: "URN:CNFX:ME:LOCKING_MECHANISM"
    interface_type: "physical-logic-coupled"
manufacturing_compliance:
  - standard: "ISO 10424-2:2007 (PETROLEUM AND NATURAL GAS INDUSTRIES - ROTARY DRILLING EQUIPMENT - PART 2: THREADING AND GAUGING OF ROTARY SHOULDERED THREAD CONNECTIONS)"
    scope: "Verified Engineering Specification"
  - standard: "API SPEC 7-2:2017 (SPECIFICATION FOR THREADING AND GAUGING OF ROTARY SHOULDERED THREAD CONNECTIONS)"
    scope: "Verified Engineering Specification"
url: "https://cnfx.com/llms/industry/machinery-and-equipment-manufacturing/product/tool-joint.md"
on_chain_sovereignty:
  contract_standard: "ERC-721-Industrial"
  metadata_hash: "5b17390b0fbb162ce406e62d7699f1d233b437741e5fb08ddc19ddb82f687f67"
  royalty_logic: "IPFS-CID-REQUIRED"
  mint_status: "logic-verified-ready"
version: "3.3.4-EXTREME-SOVEREIGN-WEB3"
---

# Industrial Specification: Tool Joint

## 1. Technical Definition
A specialized mechanical connector that attaches drilling tools to the Kelly Bar Body in drilling rigs.

## 2. Engineering Reasoning & Causal Matrix
> **Operational Intelligence**: Designed for **70-210 MPa axial load, 35-105 MPa torsional stress, -40°C to 150°C temperature**. Failure boundary: **Material yield strength threshold: 550 MPa for API Spec 7-1 Grade X, fatigue limit at 10^7 cycles: 275 MPa stress amplitude, thread engagement loss at &gt;0.5 mm radial clearance**, Mechanism: **High-cycle fatigue from cyclic loading exceeding 10^7 cycles at stress amplitudes &gt;275 MPa, thread galling due to frictional heat generation exceeding 250°C at contact surfaces, stress corrosion cracking in H2S environments above 0.05 psi partial pressure**.

### 2.1 Analytical Physics Model
Governed by the **Thin-Wall Pressure Vessel Stress Analysis**:

> **Primary Equation**: $\sigma_h = \frac{P \cdot D}{2t}$  
> **Engineering Impact**: Determines the hoop stress boundary to prevent rupture.

| Symbol | Variable Definition | Localized Reference |
| :--- | :--- | :--- |
| P | Internal Pressure | Engineering Constant |
| D | Diameter | Engineering Constant |
| t | Wall Thickness | Engineering Constant |

### 2.2 FMEA (Failure Mode & Effects Analysis)
| Event Trigger | Severity | Failure Mode | Mitigation Strategy |
| :--- | :--- | :--- | :--- |
| Thread pitch deviation exceeding 0.025 mm per 25.4 mm due to manufacturing tolerance stack-up | 8 | Premature thread wear leading to 0.8 mm radial play within 500 drilling hours | Implement coordinate measuring machine verification with 0.005 mm accuracy for all thread profiles, apply DLC coating with 0.5 μm thickness on mating surfaces |
| Resonant vibration at 85-120 Hz matching drill string natural frequency | 8 | Accelerated fatigue crack propagation from surface defects &gt;0.1 mm depth | Integrate tuned mass damper with 15 kg mass and 0.3 damping ratio, enforce maximum surface roughness Ra 1.6 μm via shot peening |

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

## 4. System BOM & Knowledge Routing
### Core Components (Recursive Links)
- [Locking Mechanism](https://cnfx.com/llms/industry/fabricated-metal-product-manufacturing/product/locking-mechanism.md) `(Standalone System)`

### Industrial DNA Context (De-duplicated)
**Complementary Dependencies**: **CNC Machining Center**, **Heat Treatment Furnace**, **Thread Rolling Machine**  
**Downstream Applications**: Drill String Assembly, Rotary Drilling Rig, Geotechnical Drilling Equipment  

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

### Q: What is the primary function of a tool joint in drilling equipment?
**A**: A tool joint serves as a specialized mechanical connector that securely attaches drilling tools to the Kelly Bar Body in drilling rigs, ensuring proper torque transmission and alignment during drilling operations.

### Q: Why is alloy steel used for tool joint construction?
**A**: Alloy steel provides exceptional strength, durability, and wear resistance required for the high-stress conditions in drilling operations, while maintaining the necessary toughness to withstand impact and fatigue.

### Q: What maintenance is required for tool joint components?
**A**: Regular inspection of the locking mechanism, sealing surface, and threaded section is essential. Proper lubrication, thread cleaning, and timely replacement of worn components ensure optimal performance and prevent drilling downtime.

## 6. Manufacturing Compliance
- ISO 10424-2:2007 (PETROLEUM AND NATURAL GAS INDUSTRIES - ROTARY DRILLING EQUIPMENT - PART 2: THREADING AND GAUGING OF ROTARY SHOULDERED THREAD CONNECTIONS)
- API SPEC 7-2:2017 (SPECIFICATION FOR THREADING AND GAUGING OF ROTARY SHOULDERED THREAD CONNECTIONS)

---
### 🛠️ Engineering Resource Access
🔗 **[Full Specification: Tool Joint](https://cnfx.com/industry/machinery-and-equipment-manufacturing/product/tool-joint)**

### 🌐 Knowledge Graph Topology
> **Node Status**: Verified Engineering Spec
> **Connectivity**: Linked to **3** standalone system nodes
> **Global Context**: Part of a 5,814 node industrial cluster within the CNFX Graph

> **Reference ID**: TOOL_JOINT | **Authority**: CNFX-2026-ST-001 | **Fingerprint**: c1eabf05
