A 6-in.-diameter SAE 1020 steel bar 30 in. long is to be machined on a lathe under the following conditions: a. For the minimum-cost case, determine the cutting speed, the tool life, the unit time per...

A 6-in.-diameter SAE 1020 steel bar 30 in. long is to be machined on a lathe under the following conditions:

a. For the minimum-cost case, determine the cutting speed, the tool life, the unit time per piece, and the cost per piece. b. For the maximum-production case, determine the cutting speed, the tool life, the unit time per piece, and the cost per piece.

(a) 1813 ft/min; 7.5 min; 2.39 min; and $1.37/piece, B = 2356 ft

(b) 2711 ft/min; 1.5 min; 2.16 min; and $1.65/piece