The conical design helps either guide the product into it, or helps secure the eyelet itself in place. Material commonly used: Aluminium oxide (Al₂O₃) The smooth, polished surface of alumina eyelets minimizes friction as the wire or cable passes through. This reduces wear on both the wire and the eyelet, improving production efficiency and product quality. The conical design helps either guide the product into it, or helps secure the eyelet itself in place. Material commonly used: Aluminium oxide (Al₂O₃) The smooth, polished surface of alumina eyelets minimizes friction as the wire or cable passes through. This reduces wear on both the wire and the eyelet, improving production efficiency and product quality.