This 30-piece hex key set, featuring 15 SAE- and 15 metric-size keys, is ideal for any job at work or home that requires durable, precision-fitting tools for loosening or tightening machine screws with a hexagonal head. Engineered with chamfered tips and made from chrome-vanadium steel for strength and rust resistance, these professional-grade hex keys are ready to tackle any task on your to-do list.