Metaldyne is a leading designer and producer of engine, driveline, and chassis products for the automotive industry. The company employs more than 7,500 people at 45 facilities in 14 countries, including 19 US facilities. The Challenge was to improve the efficiency and cut production costs in the manufacture of a diesel engine component at Metaldyne's Middleville Plant in Michigan.

* The situation - Metaldyne makes the aluminum front cover for a popular truck diesel engine, which integrates chambers for the water and oil pumps.

The part is manufactured on a five-axis CNC line equipped with six German-made twin-spindle machines using a tool package that came with the machines.

The critical operation is milling a 1.1/2in deep round chamber in the cover to receive the impeller of the integral water pump.

This was accomplished using a 50mm diameter polycrystalline diamond (PCD) tool on a HSK 63 holder.

The US$2,500 one-piece tool worked well, explained manufacturing engineer Tim Jorgensen, but when the cutting edge wore down, it had to be sent back to the supplier to be reconditioned, which cost up to US$1,200 and took two to four weeks.

As a result, the plant had to stock multiple expensive spares.

Jorgensen said: 'The tool was the highest cost in the process.

That tool cost more on the cost-per-unit basis than all the other 19 tools combined.' * The solution - Jorgensen said Metaldyne tried 'off-the-shelf' tools, which were somewhat more cost-effective but slowed the production cycle.

Recognizing that a customized tool utilizing low-cost inserts was needed, Jorgensen brought in Lovejoy Tool (as well as other tool makers) to propose a solution.

The result was Lovejoy Tool's proposal for a diamond-tipped indexible helical interpolation milling tool that cost just 10% of the tool Metaldyne had been using and also produced more parts before needing to be inexpensively reconditioned.

* The benefits - Jorgensen said the cost of the CNC milling operation was reduced to 25% of what it had cost using the old single-piece tool.

The innovation enabled Metaldyne to reduce the cost-per-part for the milling operation to 4 to 6 cents.

Another plus - Metaldyne no longer had to carry as many expensive replacement tools in stock, tying up investment and space.

Jorgensen said: 'Lovejoy Tool came up with the design for tool inserts that I liked.

Production costs were just 25% of what it had cost before.