Irwin Hanson 24640 53-Piece Machine Screw & Fractional Tap & Hex Die Set

These sets include a tap wrench, die stock, and hex rethreading dies in a range of sizes. Hex rethreading dies can be turned with a standard open-end wrench in addition to die stocks, so they're useful for hard-to-reach areas. Taps contain iron with a high carbon content. They're hard and strong, but can be susceptible to corrosion. Taps have 3 to 5 tapered threads.

Sometimes called second taps, they create threads in through holes or blind holes that are deep enough to have 3 to 5 incomplete threads. Dies create external threads in one size. Dies contain iron with a high carbon content.