Open End Wrench, Alloy Steel, Satin, Head Size 5/16 in, Overall Length 3 1/2 in, 15°, 75°/ OVERALL LENGTH: 3.250 INCHES NOMINAL LARGE END HEAD THICKNESS: 0.156 INCHES NOMINAL SMALL END HEAD THICKNESS: 0.156 INCHES NOMINAL WRENCHING SURFACE SIZE: 0.313 INCHES NOMINAL BOTH ENDS WRENCHING SURFACE SHAPE: OVAL BOTH ENDS INTERNAL SMALL END HEAD ANGLE: 15.0 DEGREES NOMINAL LARGE END HEAD ANGLE: 75.0 DEGREES NOMINAL MATERIAL: STEEL OVERALL SURFACE TREATMENT: CHROMIUM OVERALL STYLE DESIGNATOR: 104 DOUBLE HEAD