These are Aerospace Grade 6AL4V Titanium 5/16-24 Lock Nuts perfect for skateboard wheels or anywhere a 5/16-24 locknut is needed. Half the weight of steel and corrosion free. Price is for 4 pieces as shown. Super lightweight and made not from lower grade titanium but from the best Grade 5 6AL4V Titanium. We offer a complete line of M3, M4, M5, M6 and M8 Titanium screws in button head, flat head and various lengths.