This O1 Oil Hardening Tool Steel Drill Rod is a premium precision-ground round bar stock engineered for toolmakers, machinists, and fabricators who demand reliable performance and tight tolerances. Manufactured from genuine O1 tool steel, it offers outstanding oil-hardening characteristics that produce high hardness, wear resistance, and toughness once heat treated—making it ideal for punches, dies, gauges, shafts, arbors, and a wide variety of custom tooling projects. Supplied in the annealed condition for easy machining, this 3/8" diameter × 36" long drill rod features a precision-ground finish that provides smooth surfaces and consistent dimensions straight out of the package. Whether you're building fixtures, repairing equipment, creating prototype tools, or working on hobby projects, this high-quality tool steel rod gives you the strength, stability, and workability you need for professional-grade results.