Machine guards provide protection to the operator from the dangers of moving parts and debris. Guards are constructed to suit the particular dangers of a machine. The material used depends on three characteristics: strength, durability and flammability. The U.S. Occupational Safety and Health Administration, or OSHA, requires that operators be protected from dangerous parts of a machine.
According to OSHA, the best material for machine guards is typically metal. Metal guards resist sparks without the danger of melting or catching fire. Metal's higher durability and strength reduces the chance of the guard breaking.
Plastic and Safety Glass
Plastic and safety glass is used to provide a guard without sacrificing visibility. Neither is a good material for machines that produce sparks or direct heat. Plastic and safety glass is often used in combination with metal to create a guard with a window that allows the machine operator to see the machine at work.
Wood is the least common guard material. OSHA does'nt recommend using wood because of its flammability and low durability. It is used, however, when the guard will come in contact with corrosive substances. This only applies to corrosives that damage metal or plastic guards.