Grey Pneumatic Impact Sockets are made from high quality alloy steel (chrome-molybdenum). Thorough and exact heat treatment insures the correct balance of strength and durability. Grey Pneumatic Impact Sockets are tested to the highest specifications to deliver outstanding performance. Increased Strength-Transfers the pressure from the thinnest part of the socket wall toward the thicker section, resulting in increased strength. Increased Torque-Allows up to 20% more torque to be applied than on standard hex impact sockets. Easier Access to Tight Area-The shift in pressure allows us to reduce the socket wall thickness, increasing access to tight areas. Reduced Wear-The impact sockets grip the fastener across a broader contact area, reducing the chance of rounding off fasteners.