Author: Site Editor Publish Time: 2026-02-10 Origin: Site
In the automotive manufacturing industry, details often determine product quality. As a key component for door safety, the quality of door lock bolts directly affects a vehicle’s safety performance. This case study shares how optimizing the production process of stainless steel door lock bolts can improve product quality and extend die life to meet customer requirements. This case is based on the technical solution provided by Jungu precision mould.
Stainless steel door lock bolts are widely used in Volkswagen vehicle series as fastening components for door lock latches. During production, several challenges arise. Due to the inherent difficulty of processing stainless steel, die life is often affected, making it difficult to maintain stable production efficiency. Therefore, optimizing the production process and improving bolt quality and die life became a priority.
Application:
Primarily used to fasten the door lock latch on Volkswagen vehicle series.
Production Challenges:
Because this bolt is made of stainless steel, its low formability makes cold forming difficult. During production, punch pins and dies tend to wear faster than expected, resulting in unstable tool life and making the bolt hard to form consistently.
The high hardness and corrosion resistance of stainless steel make it prone to forming difficulties during production. To address this issue, higher-quality stainless steel materials were selected, and advanced phosphating surface treatment was applied to enhance bolt durability and corrosion resistance, ensuring long-term stability in use.
To overcome stainless steel processing challenges, imported die steel and alloy materials specifically designed for stainless steel were used to manufacture the dies. The use of high-quality die steel effectively extended die life and avoided the rapid wear typically seen with conventional die steel when processing hard materials.
To improve production efficiency and die life, appropriate heat treatment processes were applied to the dies to ensure durability and bolt production accuracy. At the same time, the die inner bore surface finish was processed to a mirror level, ensuring bolt dimensional accuracy and surface quality.
After the production process improvements, the forming difficulty of the bolts was effectively resolved, and die service life was significantly extended. Today, all Volkswagen vehicle models use this optimized stainless steel door lock bolt. The production process maintains high quality consistency, and die life has been notably improved.
Die polishing quality is crucial to die life. To ensure high-quality die polishing, a multi-step fine polishing process was adopted, including rough polishing, semi-finish polishing, and finish polishing, achieving excellent surface smoothness. Through this process, die service life was greatly improved.
| Polishing Method Overview:
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For high-precision irregular parts, traditional EDM processing can cause issues such as rough surfaces and carbon buildup. To solve this, mirror EDM technology was introduced, offering the following advantages:
Stable current output: avoids carbon buildup caused by unstable current; minimal electrode wear; consistent dimensional accuracy.
High surface finish: after mirror EDM, surface finish can reach level 16, suitable for subsequent polishing and ensuring high-precision machining.
Higher efficiency: mirror EDM machines are equipped with tool magazines, reducing tool change time and enabling 24-hour continuous machining, greatly improving production efficiency.
Through a series of process improvements and technical innovations, we successfully optimized the production workflow for stainless steel door lock bolts and solved multiple issues in traditional production. These improvements not only enhanced bolt quality and die life, but also provided more reliable safety assurance for Volkswagen vehicle series. At the same time, these technical achievements offer valuable experience for other automotive manufacturers.
To learn more about technical solutions for stainless steel components and die manufacturing, please visit Jungu precision mould. We are committed to providing high-quality die solutions for customers worldwide.
