Stanley 60r line of chords rule stanley 1 35 333 the line of chords scale rule incorporates a scale from 0 deg to 120 deg in 1 2 ordm increments two centre dots are provided one on each blade and with the aid of dividers the rule can be set at any angle or an existing angle can be determined line of chords the circumference scale indicates the circumference by measuring the diameter stanley 1 35 333 60r line of chords rule 60cm