Feedstock
A semi-finished material that is used to 'feed' the next process. For example continuously cast billet is the feedstock for extrusion and continuously cast rod or bar may be the feedstock for wire making.
Flotation
A mineral beneficiation technique used to concentrate ore by blowing air through a tank in which ore particles are suspended in water that contains additions that make the ore more hydrophilic. The ore clings to the bubbles and is scraped off as 'froth'.
Free Machining, Free Cutting, High Speed Machining
Terms that are used interchangeably to describe materials that can be turned, drilled or otherwise machined using high cutting speeds and feeds to leave a good surface finish with low tool wear and no appreciable build-up of swarf around the cutting tool.
The addition of Lead to Copper alloys usually improves machinability. The brass CW614N (CZ121 Pb3) has one of the fastest rates of metal removal, but ductility is compromised. This brass sets the machinability standard against which the machinability of all other alloys are measured.