These Forgefix Pipe Clips are made from heat resistant polypropylene, designed to withstand the temperature changes in most central heating systems. They are effective with temperatures of up to 100°C. They each come complete with a hardened masonry nail, which is easy to fix and durable. APPLICATION: Used when fitting most types of pipe work. Ensure when fitting that goggles are used. Polypropylene, also known as polypropene, is a thermoplastic polymer used in a wide variety of applications. An addition polymer made from the monomer propylene, it is rugged and unusually resistant to many chemical solvents, bases and acids.