This standard is no longer an American National Standard or an ASME-approved standard. It is available for historical reference only. This Standard contains the complete dimensional, mechanical and performance requirements for Metric Series Hexagon Keys and Bits of nominal sizes from 0.7 mm to 36 mm recognized as American National Standard. They are primarily intended to be used for tightening and loosening metric series hexagon socket screw products but may also be suitable for use on other products having metric hexagon socket wrenching provisions. The inclusion of dimensional data in this Standard is not intended to imply that all the products described are stock production sizes. Consumers are requested to consult with manufacturers concerning lists of stock production sizes.