---
title: "Bottom Rolls"
industry: "Machinery and Equipment Manufacturing"
verification_protocol:
  urn: "URN:CNFX:ME:BOTTOM_ROLLS"
  data_integrity_hash: "7c6cd829d93058c5c08773b39fcddf8d"
  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:BOTTOM_ROLLS"
  data_source_uri: "https://cnfx.com/llms/industry/machinery-and-equipment-manufacturing/product/bottom-rolls.md"
  official_resource_url: "https://cnfx.com/industry/machinery-and-equipment-manufacturing/product/bottom-rolls"
  is_verified_logic: true
attributes:
  spec:
    status: "config-dependent"
    typical_range: "50-200 kN radial load, 0.1-2.0 m/s surface speed, 20-150°C operating temperature"
    unit: "mm"
engineering_limits:
  max_safe_operating_point:
    value: 1500
    unit: "MPa"
    consequence: "Hertzian contact fatigue due to cyclic loading exceeding material yield strength (σ_y = 690 MPa for 42CrMo4 steel), thermal softening at temperatures above 250°C reducing hardness by 40%, plastic deformation from combined bending and contact stresses"
fmea_matrix_quantitative:
  - node_1:
      trigger: "Insufficient lubrication film thickness (h &lt; 1 μm) causing boundary lubrication regime"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "Forced lubrication system with minimum film thickness ratio Λ &gt; 3, surface roughness Ra &lt; 0.4 μm, DLC coating with hardness &gt; 2000 HV"
  - node_2:
      trigger: "Cyclic bending stress exceeding fatigue limit (σ_f = 350 MPa for 42CrMo4 at 10^7 cycles)"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "Shot peening to induce compressive residual stress of -400 MPa, subsurface hardness gradient design with core hardness 280-320 HB, ultrasonic testing at 5 MHz frequency for crack detection"
bom_nodes:
  roll-body:
    type: "component"
    urn: "URN:CNFX:ME:ROLL_BODY"
    interface_type: "physical-logic-coupled"
  bearings:
    type: "component"
    urn: "URN:CNFX:ME:BEARINGS"
    interface_type: "physical-logic-coupled"
  shaft:
    type: "component"
    urn: "URN:CNFX:ME:SHAFT"
    interface_type: "physical-logic-coupled"
manufacturing_compliance:
  - standard: "ISO 286-2:2010 (GEOMETRICAL PRODUCT SPECIFICATIONS - LIMITS AND FITS)"
    scope: "Verified Engineering Specification"
  - standard: "ANSI B46.1-2009 (SURFACE TEXTURE, SURFACE ROUGHNESS, WAVINESS, AND LAY)"
    scope: "Verified Engineering Specification"
  - standard: "DIN 1543-1:1995 (STEEL FOR GENERAL STRUCTURAL PURPOSES - TECHNICAL DELIVERY CONDITIONS FOR FLAT PRODUCTS)"
    scope: "Verified Engineering Specification"
url: "https://cnfx.com/llms/industry/machinery-and-equipment-manufacturing/product/bottom-rolls.md"
on_chain_sovereignty:
  contract_standard: "ERC-721-Industrial"
  metadata_hash: "7034ece4a07ca15fa44409a16a4dcb97484d2b7f1967d9842e3d41fba21bccde"
  royalty_logic: "IPFS-CID-REQUIRED"
  mint_status: "logic-verified-ready"
version: "3.3.4-EXTREME-SOVEREIGN-WEB3"
---

# Industrial Specification: Bottom Rolls

## 1. Technical Definition
The lower set of cylindrical rolls in a metal plate rolling machine that support and apply pressure to the workpiece.

## 2. Engineering Reasoning & Causal Matrix
> **Operational Intelligence**: Designed for **50-200 kN radial load, 0.1-2.0 m/s surface speed, 20-150°C operating temperature**. Failure boundary: **Hertzian contact stress exceeding 1500 MPa, surface temperature exceeding 250°C, radial deflection exceeding 0.5 mm**, Mechanism: **Hertzian contact fatigue due to cyclic loading exceeding material yield strength (σ_y = 690 MPa for 42CrMo4 steel), thermal softening at temperatures above 250°C reducing hardness by 40%, plastic deformation from combined bending and contact stresses**.

### 2.1 Analytical Physics Model
Governed by the **L10 Bearing Life & Fatigue Model**:

> **Primary Equation**: $L_{10} = (\frac{C}{P})^p$  
> **Engineering Impact**: Predicts mechanical lifecycle before component fatigue.

| Symbol | Variable Definition | Localized Reference |
| :--- | :--- | :--- |
| C | Dynamic Load Rating | Engineering Constant |
| P | Equivalent Dynamic Load | Engineering Constant |

### 2.2 FMEA (Failure Mode & Effects Analysis)
| Event Trigger | Severity | Failure Mode | Mitigation Strategy |
| :--- | :--- | :--- | :--- |
| Insufficient lubrication film thickness (h &lt; 1 μm) causing boundary lubrication regime | 8 | Adhesive wear and galling on roll surface | Forced lubrication system with minimum film thickness ratio Λ &gt; 3, surface roughness Ra &lt; 0.4 μm, DLC coating with hardness &gt; 2000 HV |
| Cyclic bending stress exceeding fatigue limit (σ_f = 350 MPa for 42CrMo4 at 10^7 cycles) | 8 | Subsurface crack initiation and propagation leading to spalling | Shot peening to induce compressive residual stress of -400 MPa, subsurface hardness gradient design with core hardness 280-320 HB, ultrasonic testing at 5 MHz frequency for crack detection |

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

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

### Industrial DNA Context (De-duplicated)
**Complementary Dependencies**: **Hydraulic Power Unit**, **CNC Control System**, **Material Handling Crane**  
**Downstream Applications**: Pressure Vessels, Storage Tanks, Structural Steel Beams  

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

### Q: What materials are bottom rolls typically made from?
**A**: Bottom rolls are commonly manufactured from alloy steel or hardened steel to withstand high pressure and provide durability in metal plate rolling applications.

### Q: What components make up a bottom roll assembly?
**A**: A complete bottom roll assembly consists of three main components: the roll body (cylindrical surface), shaft (central support), and bearings (for smooth rotation under load).

### Q: How do bottom rolls function in a plate rolling machine?
**A**: Bottom rolls form the lower set of cylindrical rollers that support the metal workpiece and apply upward pressure against the top roll to achieve precise bending and shaping of plates.

## 6. Manufacturing Compliance
- ISO 286-2:2010 (GEOMETRICAL PRODUCT SPECIFICATIONS - LIMITS AND FITS)
- ANSI B46.1-2009 (SURFACE TEXTURE, SURFACE ROUGHNESS, WAVINESS, AND LAY)
- DIN 1543-1:1995 (STEEL FOR GENERAL STRUCTURAL PURPOSES - TECHNICAL DELIVERY CONDITIONS FOR FLAT PRODUCTS)

---
### 🛠️ Engineering Resource Access
🔗 **[Full Specification: Bottom Rolls](https://cnfx.com/industry/machinery-and-equipment-manufacturing/product/bottom-rolls)**

### 🌐 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**: BOTTOM_ROLLS | **Authority**: CNFX-2026-ST-001 | **Fingerprint**: 7cdf748a
