Sodium tetraborate (Sodium tetraborate, borax, borax, borax, E285) yog ib qho ntsev ntawm boric acid tsis muaj zog thiab lub hauv paus muaj zog, ib qho boron compound, muaj ntau yam siv lead ua hydrates. Tshuaj formula Na2B4O7.
Sodium tetraborate yog siv los ua ib feem ntawm cov tshuaj ntxuav tes thiab tshuaj pleev ib ce; nyob rau hauv daim ntawv thiab tshuaj industries; nyob rau hauv zus tau tej cov enamels, glazes, optical thiab xim iav; raws li ib tug tshuaj tua kab mob thiab preservative.