ASME B16.3 pdf download Malleable Iron Threaded Fittings Classes 150 and 300 (a) Metal Thickness Tolerances. Metal thickness at no point in the castings shall be less than 90% of the value given in the tables. (b) Center-to-End Tolerances. Permitted tolerances on the center-to-end dimensions of the fittings are shown inTables 2 and I-2. Tolerances for end-to-end dimensions and lengths...