The main cutting force acting on a tool during a turning operation of a metal is 400 N. The turning was performed using a 2 mm depth of cut and a 0.1 mm/rev feed rate. The specific cutting pressure is:

In orthogonal cutting of steel with a 10° rake angle tool: width of cut b = 2 mm, feed t = 0.20 mm/rev, chip thickness ratio r = 0.31, vertical cutting force Fc = 1200 N, and horizontal thrust force Ft = 650 N. Using Merchant's circle diagram, what is the shear stress (τs) on the shear plane?

Calculate the rpm required for a high-speed drill of Φ20 mm to drill a plate of Mild Steel with a recommended cutting speed of 31.4 meters/minute.