This is a 5/8-18 palnut that we supply on a blanket purchase order basis to one of our aerospace customers. Per their specific specifications we have the plain steel version of this part nickel plated to QQ-N-290, with copper strike. Parts go through a 5 hour pre-bake process and also an 8 hour post-bake process at 375 degree Fahrenheit. To our customer's request all passivated and plated parts are shipped with a NADCAP cert.