MS (Mild Steel) binding wire 20 gauge is a pliable, low-carbon steel wire with a diameter of approximately 0.91 mm (0.032 inches), making it ideal for general construction purposes like bundling rebar. It's strong enough to secure materials but flexible enough for easy manual twisting and manipulation. The "20 gauge" refers to its thickness using the Standard Wire Gauge (SWG) system, with higher numbers indicating thinner wire. It's available in different forms, such as black annealed or galvanized, and is sold in various pack weights for different applications.