What are the reasons for reduction of tool life in a machining operation?
1. Temperature rise of cutting edge
2. Chipping of tool edge due to mechanical impact
3. Gradual wear at tool point
4. Increase in feed of cut at constant cutting force
Select the correct answer using the code given below:
(a) l, 2 and 3 (b) 2, 3 and 4
(c) 1, 3 and 4 (d) 1, 2 and 4