These 25mm (1") tapers are made from 316L stainless steel. We also sell these in titanium and they are color coded by gauge. Warning for 18G you must know your thread pattern for the correct screw fit. Test with a top from a 16G piece to know for sure.
18G - 0.8mm thread pattern (a unique thread pattern that some manufactures use for 18G)
18G - 0.9mm thread pattern (this happens to be the same thread pattern as 16g)
