UNITS CONVERSION FROM US CUSTOMARY UNITS TO SI UNITS AND SYMBOLS USED IN PRESTRESSED CONCRETE DESIGN Prepared by: Engr. Reyman Solas Since most engineering design text book were authored by the Americans, it is not surprising that they use US Customary units or as we know it-English units. That’s why it is imperative for us to review conversion units of most commonly used measurements for alignment to SI units which is our system of measurement that we adhere here, in the Philippines. 16,387 416,321