Constructed from chrome vanadium steel, these wrenches have more certifications than a PhD candidate... 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, and there are more... but you get the idea. This all-encompassing collection of SAE combination wrenches spans sizes from 1/4" to 1", ensuring you have the best combination of accessibility and leverage whenever you need it. Includes sizes: 1/4, 5/16, 3/8, 7/16, 1/2, 9/16, 5/8, 11/16, 3/4, 13/16, 7/8, 15/16, 1".