... hexagon boltmaterial of the product: carbon steel , stainless steel ,standard of the product: din933,din931size of the product: all sizesurface ... made of carbon steel, alloy & stainless steel, aluminum, brass or other special materials. For finishing, we provide black oxide, ... , AS, BS, JIS, GB and ISO standards, non-standard specifications or upon our customers' special requirements, in grades 4.8, 6 ...