What does the diamond on my stanley tape measure represent?
It is printed every 19 3/8 inches ( i think )
One little-known feature on most tape measures is a small black diamond that appears every 19.2 inches, known as the 'black truss' markings. This is used to mark out an equal five trusses per standard eight-foot sheet of building material. (8 feet, or 96 inches, divided by 5 is 19.2 inches.