ASME B18.2.3.2 pdf download Metric Formed Hex Screws 6.6.5 Position of Body-to-Thread. For products with cut threads, at maximum material condition, the axis of the screw body, D s (derived median line), over a length equal to the nominal screw diameter from the last scratch of thread, shall be within the positional tol- erance zone diameter specified in Table 2...