This line of high-efficiency polyurethane timing belts features steel tension member construction and is said to offer excellent flexibility, fatigue resistance, and bonding surfaces. The timing belts are constructed of many small-diameter steel filaments (down to thicknesses of 0.04 mm), which are braided in groups. This design eliminates the need for a center core wire. Tension member construction determines timing belt strength and spring rate, which, in turn, influence tooth shear strength and power transmission. This design also allows the polyurethane to fully bond all strands with the whole tension member cord, instead of only encapsulating the outer layer of the tension members and leaving voids at the inner section of the cord. These compact timing belts are built to provide enhanced strength, reliability, and accuracy as well as a long service life.