Getting the Lead Out

When strength and light weight are required in a finished part, aluminum is often the best choice for the base material. However, with impending restrictions on lead (Pb) content to satisfy European ecological norms, aluminum users are concerned with losing machinability and being forced to return to 6061 alloys with long, disturbed (stirred to separate the particles) chips. Such a transition would mean low productivity, high consumption of tools and harder chips to work with.

The challenge has been to give the aluminum industry the chance to become the only metal industry, among free cutting applications, that is 100 percent environmentally friendly without compromise and is also good for high productivity in anodizing, forging and welding processes.

In 2004, Eural Gnutti—which describes itself as the largest manufacturer of cold finished rods and bars in Europe—invented their own alloy, Eural 6026. In accordance with European ecological standards which limit lead content to 0.40 percent, Eural 6026 has been made with a lead content of between 0 and 0.40 percent.

Not only was Eural 6026 designed to match ecological standards, but the alloy also responds well to anodizing, resists corrosion, can be welded and forms excellent chips in any working condition, including drilling, free cutting, plunge cutting and plunge milling.

Since the recent tendency has been to eliminate lead in aluminum alloys, for the last two years Eural Gnutti R&D has studied a variation of their existing Eural 6026 alloy, which reduces the lead content to zero without the addition of tin. This year, the company succeeded in this challenge and released the Eural 6026 lead-free alloy, which is tin free as well. Learn more about lead-free alloys by reading this article from a past issue of PM.