When sourcing tool sets, the material composition is the primary indicator of longevity. You should prioritize Chrome Vanadium Steel (Cr-V) for hand tools like wrenches and sockets, as it offers excellent strength and corrosion resistance. For high-impact tools like screwdrivers or pliers, S2 Tool Steel is preferred for its superior hardness and resistance to shattering. Ensure that the tools have undergone heat treatment to reach a Rockwell hardness (HRC) appropriate for their function, typically HRC 42-50 for wrenches and HRC 58-62 for screwdriver bits.