As demand for advanced energy technologies continues to grow, manufacturers require CNC machining partners capable of producing highly complex components with exceptional dimensional accuracy, superior surface quality, and reliable delivery performance.

Recently, CNCTech successfully completed a precision machining project for a leading U.S.-based clean energy technology company. Due to a Non-Disclosure Agreement (NDA), the customer's identity cannot be disclosed.

This project demonstrates CNCTech's capabilities in Precision CNC Machining, Surface Treatment, and Quality Assurance for technically demanding industrial components.

Project Overview

Industry: Clean Energy Technology

Customer: Leading U.S. Clean Energy Company (Protected under NDA)

Services:

• CNC Machining

• Surface Treatment

• Quality Inspection

Material: Aluminum 6061-T651

Surface Treatment:
Chromate Conversion Coating – MIL-DTL-5541 Type I Class 3 (later optimized to Type II Class 3)

Production Volume:

• 2 Part Numbers

• 1,000 pieces per part number
  
  

Product Introduction

The component is used in a high-performance energy system where dimensional accuracy, assembly precision, corrosion resistance, and long-term stability are critical requirements.

Manufactured from Aluminum 6061-T651, the part follows ASME Y14.5-2018 GD&T standards, requiring tight process control throughout rough machining, semi-finishing, finishing, and surface treatment to ensure both dimensional accuracy and cosmetic quality.

Technical Challenges

Complex Machining Geometry

The component incorporates numerous machining features, including:

• 16 threaded holes (5/8-18 UNF)

• 4 threaded holes (M12)

• Multiple 1/4-20 UNC threaded holes

• Counterbores

• Countersinks

• Various hole diameters

The combination of multiple thread standards, deep holes, and densely positioned features significantly increased machining complexity, requiring precise control of positional accuracy, thread quality, tool deflection, and machining efficiency.

GD&T and Surface Finish Requirements

Customer specifications included:

• Flatness: 0.0005" (0.0127 mm)

• Parallelism: 0.001" (0.0254 mm)

• Perpendicularity: 0.002" (0.0508 mm)

• Surface Roughness: 32 µin (Ra 0.8 µm)

Additionally, every component had to be fully deburred, edge-broken, and cosmetically flawless prior to surface treatment.

Quality Control Requirements

Critical dimensions were verified using:

• Coordinate Measuring Machine (CMM)

• Thread gauges

• Visual inspection

• Coating inspection

to ensure every component fully complied with engineering specifications before shipment.

CNCTech's Manufacturing Solution

Multi-Stage CNC Machining Process

CNCTech's engineering team developed a multi-stage machining strategy to maximize dimensional stability while minimizing material stress and deformation.

Stage 1 – Rough Milling

The workpiece underwent five separate milling setups to complete rough machining operations.

After each setup, QC engineers inspected:

• Critical dimensions

• Thread quality

• Basic geometry

using calipers and thread gauges before releasing the part to the next operation.

This machining sequence gradually removed material while minimizing residual stress release throughout the process.

Stage 2 – Geometric Tolerance Control through Turning

Two additional turning setups were performed to control:

• Flatness

• Parallelism

• Concentricity between reference surfaces

This represented the most technically challenging stage of the project.

For energy industry applications, even dimensional deviations approaching one micron can affect product performance and operational safety.

Therefore, every component underwent comprehensive CMM inspection immediately after turning.

Whenever a measured dimension approached its tolerance limit, machining offsets were adjusted immediately before proceeding to the following operation.

This approach enabled CNCTech to maintain highly consistent precision throughout the entire production batch.

Stage 3 – Finish Machining

The final two machining setups completed:

• Remaining precision features

• All threaded holes

• Counterbores

• Countersinks

• Final dimensional adjustments

In-Process Adjustment

Critical dimensions were measured directly on the machine.

Whenever measurements approached tolerance limits, tool offsets were compensated and corrective finishing passes were performed before continuing production.

Following final machining, every component underwent another full CMM inspection prior to surface treatment.

Surface Treatment

The original engineering drawing specified MIL-DTL-5541 Type I Class 3 conversion coating.

However, because Type I utilizes Hexavalent Chromium (Cr⁶⁺), CNCTech's engineering team proactively recommended switching to MIL-DTL-5541 Type II Class 3, an environmentally friendlier alternative that still fully satisfies corrosion resistance and performance requirements.

After technical evaluation, the customer approved the proposal, demonstrating CNCTech's role not only as a manufacturer but also as an engineering partner capable of providing value-added technical recommendations.

Following surface treatment, every component underwent:

• Coating inspection

• Visual inspection

• Laser marking verification

• Final quality inspection

• Packaging

before shipment.

Project Results

CNCTech successfully achieved all project requirements:

• Full compliance with GD&T specifications

• Surface roughness of Ra 0.8 µm

• Stable dimensional consistency throughout production

• Accurate thread quality and assembly performance

• Zero assembly issues reported by the customer

• Uniform coating with no scratches or discoloration

Due to the customer's urgent production schedule, deliveries were divided into two shipments:

• First 500 units delivered after 3 weeks

• Remaining 500 units delivered after 1 month

Although the first shipment was delayed by one week due to the product's machining complexity, CNCTech rapidly optimized production scheduling and resource allocation, bringing the project back on track.

The customer highly appreciated CNCTech's responsiveness, transparent communication, and collaborative engineering support.

Conclusion

This project further demonstrates CNCTech's capabilities in Precision CNC Machining, High-Precision Manufacturing, and Surface Treatment for technically demanding industrial applications.

Beyond meeting stringent GD&T requirements, surface finish specifications, and rigorous quality standards, CNCTech proactively provided engineering recommendations and sustainable surface treatment solutions that created additional value for the customer.

With extensive experience supporting projects in the energy, semiconductor, industrial equipment, medical device, and aerospace industries, CNCTech continues to help global manufacturers succeed through advanced engineering expertise, integrated manufacturing capabilities, and an uncompromising commitment to quality.

Contact us to connect

Email: hello@cnctech.vn
Website: www.cnctech.com.vn
Phone: (+84) 868 208 111