LOCK NUT, FINISH ZINC PLATED, MATERIAL STEEL, MATERIAL GRADE/CLASS GRADE A, THREAD SIZE 5/16 IN.-18, HEX WIDTH 1/2 IN, HEX HEIGHT 11/64 IN, LOCK TYPE NYLON INSERT, DIMENSIONAL STANDARDS ASME 18.18, ASME B1.1, ASME B18.16.4, SAE J429, MATERIAL QUALITY STANDARDS ASTM F788, SYSTEM OF MEASUREMENT INCH, HEX TYPE FLANGE HEX, THREAD DIRECTION RIGHT HAND, COLOR CLEAR, INSERT MATERIAL NYLON, MAXIMUM TEMPERATURE 250 DEGREES F, PACK SIZE SMALL PACK