Flat handle needle: the handle is made of cooper or stainless steel with traditional technics. The copper handle includes two kinds of trpes: passivation and silver-coated in the surface.
平柄针：针柄采用传统工艺制作，分铜柄和不锈钢柄两种，铜柄表面有钝化和镀银两种。
2
The method, which is delicate and convenient, it is not easy to be disturbed by matrix and it is fit for determine microelement - cooper and silver in pure iron and high temperature alloy.