The present disclosure is related to a universally adjustable metal two bracket attachment system for metal fence posts to attach various types of fencing materials or fence sections is disclosed. The subject metal fence post attachment bolt and bracket system is simple and easy to install, is universally adjustable to round or square metal fences posts, by bolting onto the “off the shelf” non-adjustable fence post brackets. The subject brackets allow both full section metal fencing with the bracket mounted with the open end side ways, and three rail metal fencing with the bracket facing up.