Tie wire is a pliable, durable wire used to fasten materials together, most commonly to join rebar in construction for structural integrity. It is typically made from low-carbon, annealed steel, which is strong yet flexible, and often available in galvanized form for corrosion resistance or in other alloys like stainless steel for specialized uses. Tie wire is sold in coils, is easy to work with using tools like wire twisters, and is essential for maintaining proper alignment and stability in various applications, especially those involving concrete reinforcement.