DESCRIPTION - Black Luster® Steel Hex Head Tap Bolts provide best in class decorative appearance and better corrosion resistance than black oxide and zinc plated finishes. Resistant to 1,000 hours of salt spray per ASTM B117*. These bolts are available in Grade 5 & Grade 8*. Fully threaded tap bolts can be screwed all the way into a threaded or tapped hole. These bolts are often used in conjunction with a mating nut to fasten two or more parts together.