<p>This paper presents the results of thorough evaluations on the effects of varying boron content, plus ‘plain’ thermal analysis cup type (‘round’ vs. square’ cavity) real-time analog metrics on the properties of a soft ferritic grade of conventional ductile iron. The response metrics in addition to those of plain cup thermal analysis analog metrics are digital image analysis metallography for both the graphite nodules and matrix, ultrasonic velocity, iron chemistry and the Brinell hardnesses of both water-quenched and mold-cooled ultrasonic coupons from each sample set. The statistically proven greater nodularity resulting from greater boron content can be ascribed to the effects of nodule rounding and greater ferrite formation that occur by the natural mold cooling thru the eutectoid transformation, but are undetectable by the ‘baseline’ athermal transformation from austenite to martensite that occurs by water quenching following solidification. It is also important to note that the self-imposed prerequisite of 90% minimum threshold nodularity is necessary for the validity of the foregoing conclusions. The prerequisite of 90% minimum threshold nodularity is absolutely necessary to distinguish the eutectoid transformation effects of interest on nodule shape factor from the primal nodularity governed by solidification as measured by the water-quenched coupons. That is because the degenerate nodule shape factors in calculating poor primal nodularity following solidification will greatly predominate over any effects of the eutectoid transformation on graphite morphology. These conclusions can in turn be correlated back to the hotter and longer eutectic solidification that occurs by greater boron content.</p>