GATE Mechanical Engineering (ME) 2018 Shift 2 Solved Paper

Question : 56 of 65

Marks: +1, -0

Taylor's tool life equation is used to estimate the life of a batch of identical HSS twist drills by drilling through holes at constant feed in

20 {mm}

thick mild steel plates. In test 1, a drill lasted 300 holes at

150 {rpm}

while in test 2, another drill lasted 200 holes at

300 {rpm}

. The maximum number of holes that can be made by another drill from the above batch at 200 rpm is ______________(correct to two decimal places).

Solution:

Here tool life is represented by number of holes (H) and speed is represented by rpm(N)
Taylors Tool life equation:

V T^{n}=

constant
Since all the conditions are same for different batches, except rpm and number of holes,

N H^{n}=

another constant

150 × 300^{n}=300 × 200^{n}

n=1.71

300 × 200^{n}=200 × H^{n}

H=253.51

Go to Question:

Prev Question

Next Question