Market Background
The German automotive supply chain has undergone significant restructuring since 2024. Tier-1 suppliers, squeezed between OEM cost targets and electrification transition investments, have shifted sourcing strategies. Instead of managing dozens of small machining vendors, they're consolidating to "full-service" partners who can handle complex aluminum housings with embedded thermal management features-parts that would have been castings a decade ago but are now precision-machined for weight and performance optimization.
Client & Application Scenario
Our client, a Stuttgart-based Tier-1 supplier, needed aluminum 6061-T6 motor controller housings for a new EV platform. The part combined precision-machined mounting faces (flatness 0.02mm), threaded insert holes for M6 Helicoils, and internal cooling channels requiring 5-axis access. Annual volume: 8,000 units across 24 months, with strict PPAP Level 3 submission requirements.
Their previous supplier had struggled with thermal distortion during machining, causing inconsistent sealing surface flatness. The issue wasn't the machine-it was the sequence of operations releasing residual stress unevenly.
Our Solution
PFT's engineering team, led by our senior process engineer with 18 years of aluminum machining experience, proposed a stress-relief sequence:
Rough machining with 1.5mm stock left on all critical surfaces
Thermal stress relief at 180°C for 4 hours (documented per batch)
Finish machining in a single setup on our 5-axis cell, using hydraulic fixture clamping to minimize distortion
In-process probing after each critical feature to verify dimensional stability
Material certification and full traceability were maintained per IATF 16949 requirements. We also provided CMM reports with 100% dimensional data for the first three production batches.
Results
First-article approval achieved on second submission (first submission failed at the client's previous supplier)
Process capability (Cpk) on critical sealing surface: 1.67
Delivery consistency: 100% on-time across 18 months of production
Scrap rate: 0.3% (industry average for similar aluminum housing complexity: 2–4%)
Client Feedback & Summary
The client's quality manager noted in our Q2 2025 business review: "PFT's process documentation was more detailed than some German suppliers we've used. The stress-relief step wasn't in our original drawing, but they identified the risk and proposed the solution before we asked."
This case illustrates a principle we apply across automotive work: the drawing specifies what; the supplier must determine how. At PFT, our AS9100 and IATF 16949 systems don't just ensure compliance-they create the discipline to anticipate problems rather than react to them.