I. Project Background and Core Requirements

1.1 Industry Status and Pain Points

1.2 Core Production Requirements

• Precision requirement: Key dimensional tolerance controlled within ±0.01mm, roundness and cylindricity error ≤0.01mm to meet precision assembly needs.
• Performance requirement: Achieve "high rigidity and impact resistance" or "high wear resistance and fatigue resistance" characteristics according to load differences, with service life 30% longer than the industry average.
• Efficiency requirement: Daily output of a single production line ≥5,000 pieces, defect rate (PPM) ≤50.
• Customization requirement: Support customized production of axle pins with diameter range of φ5mm-φ80mm, different lengths and structures (stepped, through-slot, etc.).

II. Core Solution Design: Full-Process Control from Material to Finished Product

2.1 Precise Material Selection: Performance Foundation Matching Working Conditions

Application Scenarios	Recommended Materials	Core Performance Parameters	Adaptation Advantages
High-frequency rotating components (machine tool spindles, motor shafts)	GCr15 bearing steel	Surface hardness HRC60-66, tensile strength ≥1800MPa, uniform microstructure	High-purity and wear-resistant, reducing rotational friction loss and extending continuous operation time
Impact load scenarios (agricultural machinery suspension, engineering machinery pin sleeves)	20CrMnTi alloy structural steel	Surface hardness HRC58-62, core toughness ≥90J/cm2, carburized layer depth 0.8-1.2mm	"Hard outer and tough inner" characteristics, impact-resistant and not easy to fracture, adapting to bumpy working conditions
Heavy-load bearing components (automotive chassis, gearboxes)	42CrMo high-strength alloy steel	Hardness after quenching and tempering HRC28-44, yield strength ≥930MPa, fatigue strength ≥500MPa	High comprehensive mechanical properties, withstanding complex bending and torsion loads to ensure driving safety
Corrosive environments (marine machinery, food equipment)	304/316 stainless steel	Corrosion resistance ≥500h (neutral salt spray test), hardness HRC18-22	Rust and corrosion resistant, adapting to humid, acid and alkali environments

2.2 Intelligent Production Process: Core of Efficient and Precise Manufacturing

1. Intelligent blanking: CNC band saws or laser cutting equipment are used for precise cutting of raw materials according to axle pin dimensions. The blanking precision is ±0.5mm, and the material utilization rate is increased to over 95%. For long-axis products, automatic feeding devices are equipped to reduce manual intervention.
2. Rough machining forming: CNC lathe clusters are used for basic forming processes such as cylindrical turning, step processing and chamfering. The double-spindle design realizes "one clamping and double-end processing", with dimensional tolerance controlled at ±0.05mm. The production efficiency is 40% higher than that of traditional lathes.
3. Directional heat treatment: Heat treatment processes are customized according to material characteristics. Vacuum quenching furnaces are mainly used to avoid oxidation and decarburization. Induction quenching is used for local strengthening of key stress-bearing surfaces. 42CrMo material achieves "strength-toughness" balance through quenching and tempering, and GCr15 steel undergoes cryogenic treatment (-196℃) to reduce retained austenite and improve dimensional stability.
4. Precision finishing: High-precision cylindrical grinders are used for final processing, equipped with online detection devices to feedback dimensional data in real time, ensuring roundness error ≤0.005mm and surface roughness reaching Ra0.8. For axle pins with slot and hole structures, five-axis machining centers are used for precise forming.
5. Surface treatment: According to rust prevention requirements, galvanizing (neutral salt spray ≥72h), phosphating (film thickness 5-8μm) or blackening treatment is selected. Automated spraying lines are used to ensure uniform coating, with adhesion meeting GB/T 9286-1998 Grade 1 standard.
6. Assembly assistance (optional): For pre-installed axle pins, servo presses are configured for precise press-fitting, with pressure precision ±5N and displacement error ±0.05mm. The press-fitting quality is monitored in real time through force-displacement curves to avoid interference or under-pressure problems.

III. Full-Process Quality Control System: Eliminating Defects from the Source

3.1 Three-Level Inspection Mechanism

1. Raw material inspection: Each batch of materials undergoes composition analysis (spectrometer detection) and mechanical property testing (tensile and impact tests). Unqualified materials are directly returned, and test reports are retained for traceability.
2. In-process inspection: Quality inspection posts are set at key nodes of rough machining, heat treatment and finishing. The mode of "first-piece inspection + patrol inspection (every 2 hours) + last-piece inspection" is adopted. SPC (Statistical Process Control) is used for key dimensions to promptly warn of process deviations.
3. Finished product inspection: Finished products must pass full-dimensional inspection, hardness testing and surface quality inspection. Sampling is conducted for fatigue life testing (≥1 million cycles without failure). Unqualified products are managed through a closed-loop process of "identification - isolation - analysis - improvement".

3.2 Quality Traceability System

IV. Customized Services and After-Sales Support

4.1 Customization Capability

4.2 After-Sales Support

• The product provides a 12-month warranty period. For quality problems occurring within the warranty period, free replacement is offered and logistics costs are borne.
• A professional technical team is equipped to provide installation guidance and failure analysis services, assisting customers in optimizing assembly processes.
• Establish customer files, conduct regular follow-up visits on usage, and proactively provide performance upgrade suggestions.

V. Scheme Implementation and Benefit Expectation

5.1 Implementation Steps

1. Demand docking (1-2 days): Clarify axle pin parameters, working condition requirements and output needs.
2. Scheme refinement (3 days): Output bill of materials, process flow chart and cost quotation.
3. Sample trial production (3-5 days): Complete sample production and provide test reports.
4. Mass production: After sample confirmation, arrange production according to the order quantity. The daily production capacity can be expanded to 10,000 pieces according to requirements.