Sodium tetraborate (Sodium tetraborate, borax, borax, borax, E285) waa milix ka mid ah acid boric daciif ah iyo saldhig adag, boron ka mid ah unugyada caadiga ah, oo leh dhowr hydrates crystal. Kiimikada formula Na2B4O7.
Sodium tetraborate waxaa loo isticmaalaa sidii qayb ka mid ah saabuunta iyo waxyaalaha la isku qurxiyo; waraaqaha iyo warshadaha dawooyinka; soo saarista dhaldhalaalka, glazes, muraayadaha indhaha iyo midabada leh; sida jeermiska disha iyo ilaalinta.