Fairgate 18" triangular aluminum engineer's scale ruler. Rugged, professional-quality Fairgate engineering scale is made from anodized aluminum with a solid core. Printed black graduations, non-glare finish, and color-coded furrows edges. Graduated 10, 20, 30, 40, 50, and 60 parts to the inch; with left to right reading calibrations (unless otherwise noted). Fairgate #41-118 triangular engineering scales are made in the USA.