Standard Specification for Aluminum Bars for Electrical Purposes (Bus Bars) This specification covers Aluminum 1350 bar for electric conductors in the tempers. The tempers are designated as H12, H112, and H111. AP Precision Metals takes pride in offering high-quality aluminum bus bars that meet various industrial and electrical specifications. The purpose of this document is to detail the requirements of Northern Powergrid in relation to the tubular busbar systems and associated fittings detailed within this document. This document supersedes the following documents, all copies of which should be destroyed. Our products are ideal for electrical power distribution, switchgear, and renewable energy applications.