Machining Properties, Brass

[TangoCleveland]

We need to mill and turn brass fittings using Naval Brass (C46400). Our old fittings were leaded brass (C36000). Primary operations are shaping a 2.5" hex nut and turning a 1" NPT thread. Will machining properties be similar between the two brasses?

 

[TVP]

Unfortunately, no, the machining properties will not be equivalent. C36000 is the standard free-cutting brass alloy, and using an arbitrary scale of machinability, it rates as 100, whereas as C46400 naval brass is only rates as 30. The addition of lead to almost any alloy (copper, steel, aluminum) greatly improves the machinability.

I would recommend consulting Machinery's Handbook or ASM HANDBOOK Volume 16 Machining for more specific information regarding tool geometries, speeds, feeds, etc.