Whether you're tightening brake calipers or assembling furniture, the STEELMAN 55489 7-Piece 3/8-Inch Drive Metric Hex Bit Socket Set delivers the dependable grip you need. With hex bits machined from high-strength S2 steel to prevent twisting and deformation of the socket under high loads set into durable chrome vanadium steel sockets, these tools are designed for long-term service. For easy identification, each socket has easy to read size markings permanently stamped into the steel that won't wear or fade away. This set includes the following popular metric sizes: 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, and 10mm. To keep them securely attached to ratchets, extension bars, and adapters, each socket features a ball detent recess on the drive end and to ensure maximum torque transfer, the drive ends also have corner recesses that transmit applied force to the flats instead of focusing on the corners which can lead to slippage, rounding, and premature tool failure. Designed and constructed to meet or exceed ASME tool performance standards, these tools can stand up to the rigors of any professional workshop while being just as handy in the home mechanic's garage.