``Amorphous'' boron filament prepared by chemical‐vapor deposition of boron on tungsten has typical tensile strengths of 400–600 kpsi and flexural strengths of the order of 2 Mpsi, contrary to the Weibull relationship which requires that the ratio of these quantities be about 1.4. Tensile strength measurements on sections of these filaments with the tungsten boride core material removed have given numerous values in the range 1 to 1.6 Mpsi, thus demonstrating that the intrinsic strength of the boron in the filament does satisfy the Weibull criterion and that ``amorphous'' boron is one of the strongest materials known.