D-Profile Rotary Shaft, Material 303 Stainless Steel, Diameter 5/16 in, Overall Length 18 in, System of Measurement Inch, Diameter Tolerance +/-0.0620 in, Standards ANSI B17.1-1967, ASTM A-582 Cond A, Step Down Diameter Not Applicable, Step Down Diameter Tolerance Not Applicable, Straightness Tolerance 0.012 in/ft.