This paper demonstrates the applicability of small and simple specimens to measure crack-arrest toughness, KIa. Specimens used up to now were large or of complicated geometry. Using small instrumented three-point bend specimens of simple geometry, possibilities and limitations were investigated. KIa values measured on compact crack arrest specimens and, respectively, by using three-point bend specimens have been compared. The results of such investigations on steel A 533 grade B class 1 are shown.