Question:-
For tool A, Taylor’s tool life exponent (n) is 0.45 and constant (K) is 90. Similarly for tool B, n=0.3 and K=60. The cutting speed (in m/min) above which tool A will have a higher tool life than tool B is
Option (A)
26.7
Option (B)
42.5
Option(C)
80.7
Option(D)
142.9
Correct Option:
(A)
Question Solution:
Tool life Vs Cutting speed diagram shown in the fig. for the given conditions for both A & B

Tool A; Constant K = 90; xponential constant = 0.45; Tool B; Constant K = 60

Exponential constant = 0.3


At the point of intersection Va = Vb and Ta = Tb

Therefore equating the above conditions we get T = 14.89 min

Substituting the t in any tool life equation will gives the V = 26.7 m/min.

Tool life A will be always higher than tool life B when the cutting velocity is higher than 26.7 m/min.

Hence the given condition is satisfied.
question-answer-faq-2378