what is the drilling time for producing a hole in an MS sheet of 25 mm thickness using an HSS drill of 20 mm diameter? The cutting speed and feed for drill are 20 m/min and 0.25 mm/revolution respectively. Neglect time taken for setting up, approaching and travelling of tools.

what is the drilling time for producing a hole in an MS sheet of 25 mm

1.	what is the drilling time for producing a hole in an MS sheet of 25 mm thickness using an HSS drill of 20 mm diameter? The cutting speed and feed for drill are 20 m/min and 0.25 mm/revolution respectively. Neglect time taken for setting up, approaching and travelling of tools.
A.	0.314 min
B.	0.236 min
C.	0.438 min
D.	0.443 min
Answer» B. 0.236 min