Acorn Nut Instockbolts M8-1 Acorn Cap Nuts 1/2-13 Hex Cap Nuts Nickel plated steel offers a nice shiny finish and good corrosion resistance Returned infrequently. Ten (10) 1/2-13 Nickel Plated Acorn Hex Cap Nuts (BCP246) · Nickel Plated Steel When used together with a threaded fastener with an external male thread, the domed end encloses the external thread of the threaded fastener, either to protect the thread itself or to protect nearby objects from contact with the thread. For use with an externally threaded item that measures 1/2 Inch and has 13 threads per inchPackage contains 10 piecesHeight: .5475Hex Socket Drive... For use with an externally threaded item that measures 1/2 Inch and has 13 threads per inch, Package contains 10 pieces, Height: ., 5475, Hex Socket Drive 3/4 3/4-10 Cap Nut 18-8 SS – FMW Fasteners In addition, the dome gives a more finished appearance.