I ordered 7/16" bolts, both carriage and square head to replace the pivot when I restored my grandfather's peavey. The carriage bolts worked for that application, but both bolts and the nuts and lock washers were all of high quality. The black oxide coating seems durable, though I haven't tested it in the weather. The products all arrived quickly. These items I purchased are a good value for their cost. I'm not sure why the flat washers, which I didn't buy, were so expensive.