About 180|Semi-red brass or low-brass rod (about 80% copper, 20% zinc). A general-purpose copper alloy that bridges the gap between pure copper and true brass. Better machinability than pure copper thanks to the zinc content, though still not free-cutting. Good corrosion resistance and a warm reddish color. Used for architectural hardware, musical instrument components, and decorative parts. Compare to C230 red brass (85/15, richer copper color) and C260 cartridge brass (70/30, more yellow, better formability).
About Rectangular Bar|Solid rectangular cross-section stock. Functionally similar to flat bar but typically available in thicker, chunkier profiles. The naming varies by supplier — what one calls rectangular bar, another calls flat bar. Used for keys, gibs, wear strips, brackets, and any part where a rectangular starting profile saves setup time versus milling from plate.