ESDU 67014 presents the results of about 110 fatigue tests on steel and aluminium cylinders; endurance is related to the ratio of maximum shear stress at the bore to the material's tensile strength. Cylinders of En 25@ En6@ S106@ DTD 364B and DTD 683 were tested with bore diameters between 9.5 mm and 50 mm and various wall thicknesses.