Constructed from chrome vanadium steel, these wrenches have certifications: ISO 1711 which specifies minimum values for Rockwell hardness and torsional strength for hand-operated wrenches and sockets, ISO 7738 which specifies the overall length and the maximum head thickness of combination wrenches, SAE AS954-E a certification covering strength, design clearances, and torque capacity. This all-encompassing collection of combination wrenches spans sizes from 8 to 19mm, ensuring you have the best combination of accessibility and leverage whenever you need it. Includes sizes: 8, 10, 11, 12, 13, 14, 17, 19mm.