Improvement of the shrinkage of thread inner diameter after M4 aluminum nut press riveting

April 12, 2021

Project Name: Improvement of the reduction of thread inner diameter after M4 aluminum nut pressure riveting

Customer requirements: material requirements-2024 aviation aluminum

Dimension requirements-in line with drawing tolerances (unmarked dimensions must be designed and processed by yourself)

Functional requirements-increase the adaptability of the internal thread after riveting

At the same time meet the pressure riveting pull force requirements

Design requirements-refer to the project background of the customer's assembly performance design and processing drawings:

1. The client drawing fails to describe the requirements of the inner diameter of the product thread after riveting, and other requirements of the client drawing cannot be changed. The product structure must be optimized and improved in accordance with the customer's assembly requirements (the national standard is changed to non-standard);

2. The client cannot provide assembly standard parts for adaptation, and the structural verification materials need to be measured on the client site and the verification materials shall be made by themselves;

3. The outer diameter of the product needs to be pressure riveted. After pressure riveting, the inner diameter of the thread will be reduced to a certain extent. While improving the inner diameter of the thread, the pressure riveting force of the outer diameter of the product must be met to ensure that the product does not fall off under 15KG.


1. Test the change of the inner diameter of the nut after the nut is riveted and collect data, and combine the data to improve the inner diameter of the thread;

2. Go to the client to measure and collect the size data of assembly verification materials, design and produce verification materials;

3. Combine the two data to make product verification after improvement, test the thread inner diameter of the product after pressure riveting, and the product pull force after pressure riveting to meet customer requirements.

Case closed:

The product process improvement of this project, through data collection, verification of material design, product verification and other methods, solves process design problems for customers!