Kincrome Impact Sockets & Accessories are manufactured from Chrome Molybdenum Steel (Cr-Mo), hardened and tempered to perform in extreme conditions - They are designed to be used with Pneumatic and Power tools where higher torque and force is required - Kincrome Impact Sockets and Accessories meet and exceed the following international standards - ANSI, DIN 3121 & 3129 When using impact tools the following saftey precautions should be taken: - Always use protective eye wear - DO NOT hold the Socket or Accessory while the tool is in operation - DO NOT use damaged or worn Sockets or Accessories - DO NOT continue to "hammer" a fastener once it becomes tight - DO NOT use standard Sockets or Accessories on impact tools