---
title: "Structural Steel I-Beam"
industry: "Manufacture of Structural Metal Products"
verification_protocol:
  urn: "URN:CNFX:ME:STRUCTURAL_STEEL_I_BEAM"
  data_integrity_hash: "f5917d1f92049ae7a82a8f28b0970dd0"
  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:STRUCTURAL_STEEL_I_BEAM"
  data_source_uri: "https://cnfx.com/llms/industry/manufacture-structural-metal-products/product/structural-steel-i-beam.md"
  official_resource_url: "https://cnfx.com/industry/manufacture-structural-metal-products/product/structural-steel-i-beam"
  is_verified_logic: true
attributes:
  depth:
    status: "config-dependent"
    typical_range: "Yield stress: 250-345 MPa (ASTM A36), Ultimate tensile stress: 400-550 MPa, Deflection limit: L/360 for floors, L/240 for roofs (span length L in meters)"
    unit: "mm"
  flange_width:
    status: "config-dependent"
    typical_range: "Yield stress: 250-345 MPa (ASTM A36), Ultimate tensile stress: 400-550 MPa, Deflection limit: L/360 for floors, L/240 for roofs (span length L in meters)"
    unit: "mm"
engineering_limits:
  max_safe_operating_point:
    value: 200
    unit: "GPa"
    consequence: "Euler buckling instability from compressive loads exceeding critical stress, yielding from tensile/compressive stress surpassing yield strength, brittle fracture from crack propagation at stress intensity factor K_I&gt;K_IC"
fmea_matrix_quantitative:
  - node_1:
      trigger: "Compressive stress exceeding Euler critical stress σ_cr due to unbraced length L&gt;10 m with KL/r&gt;200"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "Install lateral bracing at intervals ≤ L_p=1.76r_y√(E/F_y) where r_y=40 mm (weak-axis radius), use stiffener plates at supports"
  - node_2:
      trigger: "Fatigue crack growth from cyclic loading Δσ&gt;150 MPa at stress ratio R=0.1 for N&gt;2×10⁶ cycles"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "Design with fatigue detail Category C per AISC (allowable stress range=110 MPa), implement regular NDT inspection at 5-year intervals using ultrasonic testing"
bom_nodes:
  web:
    type: "component"
    urn: "URN:CNFX:ME:WEB"
    interface_type: "physical-logic-coupled"
  flange:
    type: "component"
    urn: "URN:CNFX:ME:FLANGE"
    interface_type: "physical-logic-coupled"
  fillet:
    type: "component"
    urn: "URN:CNFX:ME:FILLET"
    interface_type: "physical-logic-coupled"
manufacturing_compliance:
url: "https://cnfx.com/llms/industry/manufacture-structural-metal-products/product/structural-steel-i-beam.md"
on_chain_sovereignty:
  contract_standard: "ERC-721-Industrial"
  metadata_hash: "12467ed973943c85cbe0c06e93ebe922d7b6929227d609c6e9248daf88467cf4"
  royalty_logic: "IPFS-CID-REQUIRED"
  mint_status: "logic-verified-ready"
version: "3.3.4-EXTREME-SOVEREIGN-WEB3"
---

# Industrial Specification: Structural Steel I-Beam

## 1. Technical Definition
Hot-rolled structural steel beam with I-shaped cross-section for load-bearing frameworks.

## 2. Engineering Reasoning & Causal Matrix
> **Operational Intelligence**: Designed for **Yield stress: 250-345 MPa (ASTM A36), Ultimate tensile stress: 400-550 MPa, Deflection limit: L/360 for floors, L/240 for roofs (span length L in meters)**. Failure boundary: **Buckling occurs at critical stress σ_cr = (π²E)/((KL/r)²) where E=200 GPa (steel modulus), KL/r&gt;200 for slender beams, yielding at σ_y=250 MPa (A36), fracture at K_IC=50-100 MPa√m (toughness)**, Mechanism: **Euler buckling instability from compressive loads exceeding critical stress, yielding from tensile/compressive stress surpassing yield strength, brittle fracture from crack propagation at stress intensity factor K_I&gt;K_IC**.

### 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 |
| :--- | :--- | :--- | :--- |
| Compressive stress exceeding Euler critical stress σ_cr due to unbraced length L&gt;10 m with KL/r&gt;200 | 8 | Lateral-torsional buckling causing sudden beam collapse | Install lateral bracing at intervals ≤ L_p=1.76r_y√(E/F_y) where r_y=40 mm (weak-axis radius), use stiffener plates at supports |
| Fatigue crack growth from cyclic loading Δσ&gt;150 MPa at stress ratio R=0.1 for N&gt;2×10⁶ cycles | 8 | Progressive crack propagation leading to fracture at flange-web junction | Design with fatigue detail Category C per AISC (allowable stress range=110 MPa), implement regular NDT inspection at 5-year intervals using ultrasonic testing |

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

## 4. System BOM & Knowledge Routing
### Core Components (Recursive Links)

### Industrial DNA Context (De-duplicated)
**Complementary Dependencies**: **Overhead Crane**, **CNC Plasma Cutting Machine**, **Welding Positioner**  
**Downstream Applications**: Building Frames, Bridge Components, Industrial Support Structures  

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

### Q: What are the main applications of structural steel I-beams?
**A**: Structural steel I-beams are primarily used in construction for load-bearing frameworks in buildings, bridges, industrial structures, and infrastructure projects where high strength-to-weight ratio is required.

### Q: What materials are available for these I-beams?
**A**: Our structural steel I-beams are manufactured using carbon steel and low-alloy steel, offering different strength and durability characteristics to meet various structural requirements and environmental conditions.

### Q: How do I determine the right I-beam size for my project?
**A**: The appropriate I-beam size depends on load requirements, span length, and building codes. Key specifications include depth, flange width and thickness, web thickness, and weight per meter. Consult with our engineers for proper sizing based on your structural calculations.

## 6. Manufacturing Compliance

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### 🛠️ Engineering Resource Access
🔗 **[Full Specification: Structural Steel I-Beam](https://cnfx.com/industry/manufacture-structural-metal-products/product/structural-steel-i-beam)**

### 🌐 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**: STRUCTURAL_STEEL_I_BEAM | **Authority**: CNFX-2026-ST-001 | **Fingerprint**: 2f97bcf3
