These Ball knobs are constructed using a Duroplast (Phenolic PF), which gives great heat and cold resistance as well as Oil and grease resistance. This makes these a strong and durable part. Especially suited for mechanical function components and mechanical engineering, these knobs have many more uses, from cabinet doors to wheel turning these knobs are a great addition or replacement to your old components. Features and Benefit: Temperature resistant -20 C to 180 C so can be used in high temperature machinery or in cold environment areas Resistant to Oil, greases, weak Acids, Petrol and Alcohol for better and wider range of uses Typical Applications: Mechanical engineering Thermally Insulating Operating Elements Cabinet and storage solutions Automotive solutions