Black-Oxide Grade 5 Steel Hex Head Screws Medium-Strength UNC Full Thread Size Customized Long

Made from Grade 5 steel, these screws are suitable for fastening most machinery and equipment. Dimensions meet ASME B18.2.1 specifications. Grade 5 steel hex head screws are marked with three radial lines. Length is measured from under the head. Black-oxide steel screws are mildly corrosion resistant in dry environments. Zinc-plated steel screws resist corrosion in wet environments. Black corrosion-resistant-coated steel screws resist chemicals and salt spray per ASTM B117. T Screws that meet ASTM A449 or SAE J429 comply with specifications and testing requirements for material quality. Match the thread spacing of mating components. Coarse threads are the industry standard; choose these screws if you don’t know the threads per inch. Fine and extra-fine threads are closely spaced to prevent loosening from vibration; the finer the thread, the better the resistance.