Manufactured from chrome vanadium steel with a highly polished mirror finish. Mirror finish prevents oil and dirt from adhering to the spanner, making for easier cleaning and preventing rust. Made to American Federal Standards, extra thick heads offer higher torque forces to be applied therefore improved performance. Conform to ASME B107.9. | | Contents | 7 Piece Metric: 6 x 7, 8 x 9, 10 x 11, 12 x 13, 14 x 15, 16 x 17 and 18 x 19mm.