Gray iron contains graphite flakes that support damping and machinability. Ductile iron uses nodular graphite to improve tensile strength and impact resistance.
Specify the grade and evidence
Define the governing material standard, grade, heat treatment when applicable, test coupons, inspection records, and critical geometry. A generic callout for cast iron is rarely enough for a controlled production program.
Source: [https://redstonemanufacturing.com/grey-vs-ductile-iron](https://redstonemanufacturing.com/grey-vs-ductile-iron)
