Hydrofluoric Acid, 70%, CAS 7664-39-3, (also known as Hydrogen Fluoride) has the chemical formula HF. Hydrofluoric Acid is extremely hazardous and sale is restricted. HF Acid is widely used as an intermediate in industrial chemical manufacturing, mining clarification, oil refining catalyst production, glass manufacture and finishing, and silicon chip manufacturing. It is also used in a number of chemical preparations for metal pickling, etching, and buffing and in ceramic and porcelain applications for restoration. **Custom concentrations and blends of HF chemistry are available from Florida Chemical.