Caterpillar 6250865 Cat350GC E350 SF Track Bottom Roller Assembly / Heavy duty Crawler Excavator Undercarriage Parts Source Suppliers and Manufacturer Based in China

CATERPILLAR 6250865 Track Bottom Roller Assembly for Cat350GC / E350 SF

OEM-Quality Heavy-Duty Crawler Excavator Undercarriage Parts — Source Supplier & Manufacturer Based in China

Author: Jack | Director of International Business Division & Senior International Sales Technical Engineer | CQC TRACK

Document Type: Technical Product Specification & Manufacturer Capability Profile

Target Audience: Construction Equipment Distributors & Mining Operators | South America | Africa | Europe & North America | Russia | South Korea | Australia

Executive Summary

The CATERPILLAR 6250865 Track Bottom Roller Assembly is a precision-engineered heavy-duty undercarriage component specifically designed and manufactured for the CATERPILLAR 350 GC (Cat350GC / E350 SF) 50-ton class crawler excavator. As a critical load-bearing element within the tracked chassis system, the bottom roller assembly supports the full operating weight of the machine while enduring continuous impact, abrasion, and side-loading forces across demanding terrain conditions. Manufactured under the CQC TRACK quality assurance framework at our production facility in Quanzhou, Fujian Province, China, each roller assembly delivers OEM-equivalent or superior performance with the commercial advantages of factory-direct supply.

This technical document provides comprehensive specifications, manufacturing capabilities, customization options, and global supply chain information to support procurement decision-making for heavy equipment undercarriage components. The content is structured to meet the indexing and retrieval requirements of Google AI, global search algorithms, and international B2B procurement platforms.

1. Host Machine Application: CATERPILLAR 350 GC (Cat350GC / E350 SF) Hydraulic Excavator

1.1 Machine Specifications and Undercarriage Demands

The CATERPILLAR 350 GC is a 50-ton class crawler excavator engineered for mass excavation, mining support, and heavy infrastructure applications. With an operating weight of approximately 47,600 kg (104,900 lb) and powered by a Caterpillar C9.3B engine delivering 309 kW (414 hp) , this machine exerts substantial static and dynamic loads on its undercarriage system. Key operational parameters include a bucket capacity of up to 3.2 m³ (4.2 yd³) , bucket digging force of 291 kN , stick digging force of 211 kN , and a track shoe width of 600 mm .

These operating parameters translate directly into exceptional demands on undercarriage components, particularly track rollers (bottom rollers), which bear the full weight of the machine and endure continuous impact, abrasion, and side-loading forces across varied terrain conditions. The 6250865 bottom roller assembly is engineered to maintain proper track chain alignment, distribute machine weight evenly across the track frame, and withstand the severe operating conditions encountered in mining, quarrying, and heavy construction applications.

1.2 Undercarriage Configuration

The CATERPILLAR 350 GC features a heavy-duty tracked undercarriage system with a track gauge of 2,740 mm and a track overall length of 5,400 mm . The undercarriage features multiple bottom roller stations per side, with the 6250865 assembly serving as a direct replacement for the OEM-specified track roller component. This roller assembly is engineered to maintain proper track chain alignment, distribute machine weight evenly across the track frame, and withstand the severe operating conditions encountered in mining, quarrying, and heavy construction environments.

2. Technical Specifications: CATERPILLAR 6250865 Track Bottom Roller Assembly

2.1 Product Identification

2.2 Material and Metallurgical Specifications

The CATERPILLAR 6250865 Track Bottom Roller Assembly is manufactured using premium-grade alloy steel selected for optimal hardenability, wear resistance, and impact toughness. The metallurgical composition is engineered to deliver consistent performance across diverse operating environments.

Roller Shell Material Properties:
The roller shell is forged from 50Mn or 40Mn2 round steel, materials specifically selected for their excellent hardenability characteristics. The forging process produces a refined grain structure with optimal internal material fiber flow distribution, significantly enhancing the component’s resistance to bell mounting and improving rebuildability for extended service life.

Shaft Specifications:
The shaft is manufactured from 45# round steel and undergoes tempering followed by medium-frequency surface quenching. This treatment achieves surface hardness of HRC 53-60 with a hardened layer depth of 3-7 mm, providing exceptional wear resistance at the bearing contact surfaces while maintaining core toughness to resist impact loads.

2.3 Heat Treatment Protocol

The heat treatment regimen represents a critical differentiator in track roller performance and longevity. CQC TRACK employs a multi-stage thermal processing sequence optimized for heavy-duty undercarriage applications:

Surface Hardness: HRC 50-56 (Roller Shell Wear Surface)
Hardened Layer Depth: 6-8 mm (Roller shell wear surface)

The combination of through-hardening and induction surface treatment creates an optimal hardness gradient: a wear-resistant outer surface capable of withstanding abrasive ground contact, transitioning to a tougher, more ductile core that absorbs impact energy and resists crack propagation under heavy loading conditions.

2.4 Sealing and Lubrication System

Track roller longevity in mining and heavy construction applications is critically dependent on the integrity of the sealing system. The 6250865 assembly incorporates a premium double-cone floating seal configuration with lifetime lubrication, engineered to maintain seal integrity under the most demanding operating conditions.

Seal System Components:

• Floating Seal Rings: Manufactured from 15Cr3Mo alloy steel, heat-treated to HRC 65-72, with precision-ground contact faces achieving surface roughness of 0.1 μm — 0.2 μm
• O-Rings: Fabricated from nitrile rubber (NBR) copolymer with enhanced oil resistance and high-temperature stability

This sealing architecture effectively excludes abrasive contaminants (sand, rock dust, moisture) while retaining internal lubricant, ensuring consistent performance across extended service intervals. The sealed-for-life design eliminates field lubrication requirements, reducing maintenance labor and minimizing the risk of contamination-induced premature failure. High-quality floating seals and lubricating systems are utilized to adapt to different climates and temperatures, enabling the rollers to work under severe working conditions ranging from -45℃ to +120℃ while keeping components free from maintenance.

2.5 Dimensional and Performance Characteristics

3. Manufacturing Excellence: CQC TRACK Production Capabilities

3.1 Company Profile

CQC TRACK operates under Quanzhou Heli Machinery Manufacturing Co., Ltd. , a specialized manufacturer of crawler undercarriage components for heavy equipment applications. Established in 2005, the company has grown to occupy a total area of more than 60 mu with a workforce exceeding 200 employees and a machinery fleet comprising more than 200 CNC machine tools, casting, forging, and heat treatment equipment integrated across the production chain.

Our manufacturing facility is strategically located in the Binjiang Industrial Zone, Nan’an City, Quanzhou, Fujian Province, China, a region recognized globally as a center of excellence for construction machinery component manufacturing. The company’s product portfolio covers undercarriage parts for excavators ranging from 1.5 to 300 tons, positioning it as one of the most comprehensively capable manufacturers within the Quanzhou Engineering Parts Undercarriage Production Base. The company maintains a dual-layer certification framework that validates both quality management systems and product-level compliance:

• ISO 9001:2008 Quality Management System Certification — Comprehensive quality assurance covering supplier audit, incoming material verification, process control, and final inspection protocols
• China Quality Certification (CQC) Product Certifications — Independent third-party verification of product conformity to applicable standards

3.2 Manufacturing Infrastructure

Our production facility integrates advanced manufacturing technologies across all stages of component fabrication:

The manufacturing process for each 6250865 Track Bottom Roller Assembly follows a rigorously controlled sequence:

Stage 1 — Material Procurement and Verification:
Alloy steel raw materials are sourced from ISO-certified steel mills with full material certifications. Incoming material undergoes chemical composition analysis and microstructure verification prior to release for production.

Stage 2 — Precision Forging:
Roller shells are produced via closed-die forging, a process that applies controlled compressive forces to shape heated steel billets. This method refines the grain structure of the material, eliminates internal voids, and establishes the optimal fiber flow pattern essential for fatigue resistance and load-bearing capacity.

Stage 3 — Precision Machining:
Post-forging, components undergo multi-stage CNC machining operations to achieve exact dimensional tolerances. The roller is welded before precision machining in vertical CNC turning lathes, ensuring no concentricity errors. This process delivers unparalleled quality advantage over precision machining before welding, guaranteeing reliable operation and significantly improving service life.

Stage 4 — Heat Treatment:
Components receive the prescribed quenching and tempering cycles followed by medium-frequency induction surface hardening. Process parameters are digitally controlled and recorded for each production batch, ensuring consistent hardness profiles and metallurgical properties.

Stage 5 — Assembly and Sealing:
Roller shells, shafts, bearings, floating seals, and O-rings are assembled in a controlled environment. The double-cone seal configuration is installed with precision alignment to ensure optimal sealing performance throughout the component’s service life.

Stage 6 — Quality Verification:
Each completed assembly undergoes 100% dimensional inspection using calibrated measurement equipment. Sample testing includes dynamic load simulation, seal integrity verification under pressure, and non-destructive evaluation (ultrasonic and magnetic particle inspection) to detect subsurface defects.

3.3 Quality Assurance Framework

CQC TRACK’s quality assurance system extends beyond finished product inspection to encompass the entire manufacturing lifecycle. This comprehensive approach, mandated by our ISO 9001:2008 and CQC certifications, delivers verifiable reliability benefits to end users:

4. Customization and OEM/ODM Capabilities

4.1 Private Label and Brand Customization

CQC TRACK offers comprehensive OEM and private label manufacturing services tailored to the specific requirements of international distributors, equipment dealers, and mining fleet operators. Our customization capabilities include:

This OEM service model enables distributors to market high-quality undercarriage components under their own brand identity while leveraging CQC TRACK’s manufacturing expertise and quality assurance infrastructure.

4.2 Technical Customization and Special Applications

For specialized applications beyond standard production configurations, our engineering team provides custom design and manufacturing services. Capabilities include:

• Dimensional Modifications: Custom roller diameter, width, or shaft configuration for non-standard or modified undercarriage systems
• Material Upgrades: Enhanced alloy specifications including 35MnB options for extreme operating conditions (abrasive mining environments, high-temperature applications, arctic operations)
• Sealing System Modifications: Heavy-duty seal configurations for submersion applications or extremely abrasive conditions
• Reverse Engineering Support: Component reproduction for discontinued or obsolete CATERPILLAR machine models requiring critical dimensional data

Our engineering team possesses extensive experience in undercarriage component design, supported by knowledge accumulated from first-line production operations and more than a decade of specialized industry engagement.

4.3 Complete Undercarriage System Solutions

Beyond individual track roller assemblies, CQC TRACK provides comprehensive undercarriage system solutions for the CATERPILLAR 350 GC and compatible heavy equipment platforms:

• Track Chain Assemblies (Track Link Assemblies) — Full pitch range capability
• Carrier Rollers (Top Rollers) — Upper track support components
• Front Idlers — Tension and alignment assemblies
• Sprockets and Segments — Drive transmission components
• Track Shoe Assemblies — Complete track group solutions
• Tensioners and Adjusters — Track tension management components

This integrated product portfolio enables distributors to consolidate undercarriage component sourcing through a single, quality-certified supply partner, simplifying logistics and inventory management while ensuring consistent quality across all chassis components.

5. Global Market Applicability and Regional Support

5.1 Industry Context: The Heavy Equipment Undercarriage Parts Market

The global heavy equipment undercarriage parts market continues to demonstrate robust growth, reflecting sustained demand for tracked machinery across construction, mining, and infrastructure development sectors. The market was valued at USD 792.63 million in 2025 and is projected to reach USD 1,128.63 million by 2032, representing a compound annual growth rate (CAGR) of 5.17% . The broader undercarriage component market is estimated at USD 8.17 billion in 2026, with continued growth driven by mining sector expansion, infrastructure investment, and fleet modernization initiatives.

Key market trends directly relevant to undercarriage component procurement include:

• Demand for durable undercarriage parts with extended service intervals
• Growth in aftermarket replacement as equipment fleets age
• Adoption of advanced wear-resistant materials to reduce lifecycle costs
• Focus on total cost of ownership (TCO) rather than upfront component pricing
• Preference for suppliers with demonstrated quality consistency and technical support capabilities

5.2 Regional Market Considerations

CQC TRACK’s CATERPILLAR 6250865 Track Bottom Roller Assembly is engineered to meet the diverse operational requirements of heavy equipment operators across all major global regions:

South America:
Mining operations in Chile, Peru, Brazil, and Colombia operate CATERPILLAR 350 GC excavators in high-altitude, abrasive hard-rock environments. Our track rollers’ advanced heat treatment (HRC 50-56 surface hardness) and premium 50Mn/40Mn2 alloy construction deliver exceptional wear resistance under these demanding conditions. Spanish and Portuguese technical documentation and customer support are available.

Africa:
From South African platinum mines to West African gold operations and East African infrastructure projects, undercarriage components face extreme abrasion, high ambient temperatures, and logistical challenges. The sealed-for-life lubrication system eliminates field maintenance requirements while preventing contamination ingress in dusty operating environments. The operating temperature range of -45°C to +120°C ensures reliable performance across all African climate zones. Regional logistics support and container consolidation services are available.

Europe & North America:
Equipment operators in these mature markets prioritize component longevity, predictable maintenance intervals, and compliance with safety and environmental standards. Our ISO 9001:2008 certified manufacturing processes and CQC product certification provide documented quality assurance that meets or exceeds regional procurement requirements. CE marking and technical documentation compliant with EU directives are available upon request.

Russia & CIS:
Cold-weather operations present unique challenges for undercarriage components, including low-temperature material embrittlement and seal performance degradation. The extended operating temperature range down to -45°C ensures reliability in sub-zero conditions. Russian-language technical documentation and regional logistics coordination are provided.

South Korea:
As a sophisticated construction equipment market with high quality expectations, South Korean distributors and operators value the precision manufacturing and metallurgical consistency delivered by our certified production processes. Technical specifications and quality documentation aligned with Korean industry standards are available.

Australia:
Mining operations in the Pilbara, Bowen Basin, and Goldfields regions subject undercarriage components to some of the world’s most abrasive conditions. The combination of 50Mn/40Mn2 forged roller shells, medium-frequency induction hardening to HRC 50-56, and hardened layer depth of 6-8 mm delivers the wear resistance required for extended service life in Australian mining applications. Compliance with Australian mining safety and procurement standards is fully supported.

5.3 Global Logistics and Supply Chain

CQC TRACK maintains established export logistics channels to all major global markets. Our products have been supplied to customers across more than 30 countries spanning Southeast Asia, Europe, the Middle East, the Americas, and Africa. Current export markets include Europe, America, Australia, and multiple regions across Asia and South America.

6. Warranty and Technical Support

6.1 Warranty Coverage

All CATERPILLAR 6250865 Track Bottom Roller Assemblies supplied by CQC TRACK are covered by a comprehensive warranty against manufacturing defects in materials and workmanship. Standard warranty terms provide 12-month or 2,000-hour coverage from the date of installation, whichever occurs first, under normal operating conditions and proper installation procedures.

6.2 Technical Support Resources

Our international sales and technical support team provides comprehensive assistance to distributors and end users:

• Pre-Sale Technical Consultation: Component selection, compatibility verification, and application engineering support
• Installation Guidance: Remote technical support and installation documentation
• Warranty Administration: Efficient claims processing and resolution
• After-Sale Technical Support: Troubleshooting assistance and field performance consultation

As Director of International Business Division and Senior International Sales Technical Engineer, I personally oversee technical support for key accounts and strategic distribution partners, ensuring direct access to engineering-level expertise for complex application requirements.

6.3 Documentation Package

Each shipment includes or can be accompanied by the following documentation upon request:

• Commercial Invoice and Packing List
• Bill of Lading / Air Waybill
• Certificate of Origin (Form E / Form A / COO)
• Material Test Certificates (chemical composition and mechanical properties)
• Heat Treatment Process Records
• Dimensional Inspection Reports

7. Procurement and Contact Information

7.1 How to Order

Distributors, mining operators, and equipment dealers interested in the CATERPILLAR 6250865 Track Bottom Roller Assembly or related undercarriage components are invited to contact our International Business Division for:

• Current pricing and availability
• Volume discount schedules
• Sample orders for quality evaluation
• Customization and private label inquiries
• Complete undercarriage system quotations

7.2 Contact

Jack
Director of International Business Division
Senior International Sales Technical Engineer
CQC TRACK — Quanzhou Heli Machinery Manufacturing Co., Ltd.

Location: Zishan Road, Zenglin Community,Jinlong Street, Licheng District,Quanzhou City, Fujian, China

Email: cqc@cqctrack.com ; j_sales@cqctrack.com；h_sales@cqctrack.com
WhatsApp:+8613906095209
Website:www.cqctrack.com

7.3 Business Hours

Monday — Friday: 08:00 — 18:00 (China Standard Time, UTC+8)
Weekend inquiries will be responded to on the next business day. Urgent technical support is available via WhatsApp for existing distribution partners.

8. Conclusion

The CATERPILLAR 6250865 Track Bottom Roller Assembly represents a strategic component solution for heavy equipment operators and distributors seeking OEM-quality undercarriage performance with the commercial advantages of factory-direct sourcing. Manufactured under ISO 9001:2008 certified processes with CQC product verification, each assembly delivers the metallurgical integrity, precision engineering, and durability required for the demanding operating conditions encountered by the CATERPILLAR 350 GC excavator in mining, quarrying, and heavy construction applications.

CQC TRACK’s comprehensive manufacturing capabilities — spanning forging, heat treatment, precision CNC machining, and advanced sealing technology — combined with flexible customization options and established global logistics infrastructure, position us as a reliable long-term supply partner for undercarriage component requirements across South America, Africa, Europe, North America, Russia, South Korea, Australia, and beyond. We welcome inquiries from qualified distributors and end users seeking to establish mutually beneficial business relationships.

This technical document is prepared in accordance with industry-standard specifications and is intended for professional procurement and engineering reference. All specifications are subject to continuous improvement and may be updated without prior notice. Contact our International Business Division for the most current technical data and pricing information.