160000 pounds per square inch minimum tensile strength, 99.0 degrees minimum and 101.0 degrees maximum countersink angle, navy special project part name assigned by controlling agency, steel comp e4340 or steel comp 4140 or steel comp 8740 or steel comp 8735 or steel comp 6150 or steel comp 4130 overall material, mil-s-5000 mil spec 1st material response or mil-s-5626 mil spec 2nd material response or mil-s-6049 mil spec 3rd material response or mil-s-6098 mil spec 4th material response or mil-s-8503 mil spec 5th material response or mil-s-6758 mil spec 6th material response overall material document and classification, qq-p-416 ty 2 cl 2 fed spec single treatment response overall surface treatment document and classification

A screw, machine or screw, cap, socket head whose unthreaded portion is of specified grip length, plated or unplated, and is machined to a tolerance of one thousandth (0.001 in.) (0.025 mm) or less of a specific diameter for items (1.000 in.) (25 mm) or less in diameter. Items over (1.000 in.) (25 mm) in diameter shall have a tolerance of fifteen ten thousandths (0.0015 in.) (0.038 mm) or less. The nominal major diameter of the threads shall be at least one thousandth (0.001 in.) (0.025 mm) below the minimum shank diameter, but not below the minimum major diameter for applicable class of fit, as shown in the screw thread standards, fed std h28 and/or other nationally recognized standards. The head is designed to be held or driven with an inserted driver. It is not designed for rotation by the thumb and fingers. A locking feature may be incorporated in the design of the head or threads.