1) A bar of steel 3 in (76.2mm) in diameter is to be machined at 90 fpm (0.5 m/sec). What spindle speed should be used?
Assuming a 0.020" (0.508 mm) feed per revolution and 0.062 in. (1.575 mm) depth of cut to machine a 2 in. (50.8mm) diameter bar of SAE 1020 low carbon content plain carbon steel, calculate the metal removal rate on cubic inches per minute (mm2/sec) as a function of the cutting speed. If necessary, make an additional assumption.
2) A 2." (50.8 mm) diameter rod turning at 120 rpm is to be cut off by a tool having a feed of 0.004 in. per revolution (0.1 mm/rev). Calculate the cutting time.