Case Study: Supplier Switch Reduced Finished Part Cost

Customer: North American industrial equipment OEM Program: Aluminum gearbox cover and machined mounting plate Annual volume: 36,000 pieces/year Material: A380 aluminum Scope: Tool transfer, HPDC production, CNC machining, powder coating, export packaging

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The Procurement Problem

The buyer had an incumbent supplier that could cast the part, but machining was subcontracted to a separate shop. This created three recurring problems:

1. Dimensional disputes between the casting supplier and machining supplier
2. Long correction loops when sealing faces or tapped holes failed inspection
3. Rising finished-part cost after multiple freight and handling steps

The buyer wanted one supplier to own the complete finished component.

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KastMfg's Review

KastMfg audited the transferred tooling, inspected the critical cavity areas, and compared the casting datum scheme against the machining drawing. The main finding was that the original casting had insufficient machining allowance on one sealing face, causing occasional cleanup failures.

KastMfg recommended:

• Minor tool correction to add stable machining allowance
• New CNC fixture referencing cast datum pads
• First article inspection focused on flatness, thread position, and sealing face cleanup
• Packaging change to protect coated surfaces during ocean shipment

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Implementation

The transferred tool was qualified on a matching tonnage machine. KastMfg then ran a controlled first article batch, machined the parts in-house, and submitted dimensional reports with photos of the fixture and packaging method.

The buyer approved production after one correction loop.

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Results

Metric	Result
Finished part cost	Reduced by 18% versus previous supply chain
Supplier count	Reduced from 3 suppliers to 1
Machining rejection	Reduced after datum and allowance correction
Communication loop	One project engineer owned casting and machining
Shipment condition	Surface damage reduced after packaging change

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Why It Worked

The cost reduction did not come from casting price alone. It came from eliminating handoffs between casting, machining, finishing, and packaging. One accountable supplier could identify the process root cause and quote the finished component instead of a partial operation.

For similar projects, see die casting tool transfer and CNC machining for die casting parts.

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Supplier switch inquiry: yaoqingpu1983@gmail.com | +86 138 1403 4409 | No.6, Rungu Road, Nanjing, China