# Alloys to Avoid ### Alloys to avoid for dry milling Based on testing and experience, the following aluminum types tend to be **poor materials** for dry milling: * **5083** * **high-purity aluminium** * **cast aluminium or unknown scrap** This doesn’t mean these materials can never be machined — only that they often introduce unnecessary difficulty when learning, testing strategies, or aiming for repeatable results under dry conditions. *** ### What makes an alloy problematic on compact machines Dry milling relies on **clean cutting, stable chip formation, and controlled cutting forces**. Alloys that tend to cause problems often share one or more of the following traits: * **smearing instead of shearing**, leading to poor surface finish * **uneven tool loading**, increasing vibration and wear * **high tendency for built-up edge**, especially without coolant * **inconsistent material structure**, making results unpredictable These effects are hard to compensate for with parameter changes alone. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://miwicnc.gitbook.io/miwicnc/materials/aluminium/alloys-to-avoid.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.