Hex Socket Head Cap Screws Package M2 M2.5 M3 M4 M5 M6 M8 M10 as much as 1140 DIN912 Black 12.9 Grade Carbon Metal Bolts Nuts Assortment Made of top of the range carbon metal 12.9, it's anticorrosive and delightful as properly. As well as, it may be used to measure the standard of thread with stop-gauge.