Non-standard customized rivet solutions: overcoming the difficulties of stainless steel and aluminum composite processing

Client and Project Overview

Industry Background and Client Needs

The client is a leading company in Kyrgyzstan that specializes in mold manufacturing and oversized metal parts production, serving the construction, automotive and industrial equipment fields. As the market demand for lightweight, high-strength metal connectors grows, the client needs to develop a non-standard customized composite rivet for high-precision metal plate connection scenarios.

Project Goal

 

Design and mass produce a dual-material rivet consisting of a stainless steel 304 shaft core and an aluminum 6061-T6 shell, with the following requirements:

Ensure seamless assembly of two different materials;

Dimensional tolerance is controlled within ±0.05mm;

Meet the requirements of harsh working conditions such as corrosion resistance and shear resistance.

Product design and technical parameters

Rivet structure and application scenarios

• Material combination: stainless steel shaft core (high hardness) + aluminum shell (lightweight);
• Function: specially designed for permanent connection of metal plates (such as steel plates and aluminum plates), suitable for building frames, heavy machinery assembly and other fields;
• Advantages: combines the durability of stainless steel with the lightness of aluminum, reducing the overall structural weight.

Step-by-step analysis of the manufacturing process

Stainless steel shaft core processing:

• Use automatic lathes to precisely turn stainless steel 304 bars to ensure that the shaft diameter tolerance is ≤±0.03mm.

Aluminum shell molding:

• CNC lathes process aluminum 6061-T6 billets and complete internal threads and external grooves in stages.

Composite assembly:

• Use hydraulic pressing process to calibrate the coaxiality of the stainless steel shaft and the aluminum shell through customized fixtures.

Production Challenges and Innovative Solutions

Core Difficulty: Aluminum Deformation and Uncontrolled Tolerance

Aluminum 6061-T6 is a relatively soft material. During CNC machining and pressing, it is easy to cause deformation of the shell due to stress concentration, causing the following problems:

• The clearance between the internal thread and the stainless steel shaft is uneven;
• The outer diameter of the finished product exceeds the tolerance range (±0.05mm).

Engineers’ Breakthrough Solution

With 22 years of metal processing experience, the team overcame technical barriers through the following measures:

Phase-based Processing Optimization:

• The aluminum shell is divided into two stages: rough machining (reserving 0.1mm margin) and fine machining (low temperature cooling environment) to reduce thermal stress deformation;

Customized fixture design:

• Develop a hydraulic dynamic balancing fixture to ensure that the aluminum shell is evenly stressed during pressing;

Full-process detection system:

• Introducing a laser scanner to monitor key dimensions in real time, reducing the defective rate from 12% to 0.5%.

Project results and customer feedback

Trial order verification and mass production

• The first phase delivered 1,000 rivets, 100% of which passed the customer's salt spray test (500 hours) and tensile strength test (≥450MPa);
  

• Customer evaluation: "It solved the long-standing problem of heterogeneous material assembly that we faced, and the accuracy far exceeded expectations."
• Batch order confirmation: 300,000 pieces of demand, and the annual procurement volume is expected to exceed 2 million pieces.

Why choose us?

• Technical expertise: 10+ years of experience in customizing non-standard metal parts, proficient in composite processing of different materials;
• Equipment capabilities: fully automatic lathe + five-axis CNC center, supporting one-stop production of complex structures;
• Quality commitment: ISO 9001 certification, traceable from design to delivery.

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