# A 50 mm diameter bar of steel was turned at 284 rpm and tool failure occurred in 10 minutes. The speed was changed to 232 rpm and the tool failed in 60 minutes. Assuming straight line relationship exists, what cutting speed should be used to obtain a 30 minutes tool-life

1.  222 rpm

2.  242 rpm

3.  252 rpm

4.  272 rpm

4

252 rpm

Explanation :
No Explanation available for this question

# For the work materials A and B, following tool life data have been recorded. Cutting speed m/min Feed mm/rev Depth mm Tool-life(min) 75 30 0.1 0.1 1.5 1.5 A 20 100 B 20 145 Then based on cutting speed for 60 min tool-life, the machinabilitty of B is better than A by

1.  10.55

2.  12.55

3.  14.55

4.  16.55

4

12.55

Explanation :
No Explanation available for this question

# If the tool life relationship for HSS tool is VT1/8 = C1, and for tungsten carbide is VT0.2 = C2, and tool life for both at cutting speed of 25 m/min is equal and is 3 hours in each case, what is the ratio of their lives at a speed of 32 m/min

1.  1.08

2.  1.58

3.  2.08

4.  2.58

4

2.08

Explanation :
No Explanation available for this question

# In a turning operation the tool life of the carbide tool was found to be 20 min and 100 min at cutting speeds of 120 m.min and 80 m/min respectively. What will be the tool life of that tool under the same condition but at a cutting speed of 100 m/min

1.  31 mins

2.  36 mins

3.  41 mins

4.  46 mins

4

41 mins

Explanation :
No Explanation available for this question

# The tool life of a single point cutting tool has been found to be 1000 sec at a cutting speed of 0.5 m/s. How many piece is 50 mm diameter and requires to be turned over a length of 80 mm using a feed of 0.1 mm/rey and a cutting speed of 0.5 m/s (Approach and overshoot are neglected)

1.  2

2.  3

3.  4

4.  6

4

4

Explanation :
No Explanation available for this question

# A simple cutting tool has 900 rake angle and 30 clearances angle. The maximum length of the blank wear allowed before regrinding is 1 mm, Assuming the volume rate of wear from the flank face of the tool to be constant, what will be the % increase in the tool life if the clearance angle is increased to 70

1.  12.4 %

2.  13.4 %

3.  15.4 %

4.  18.4 %

4

13.4 \%

Explanation :
No Explanation available for this question

# A mild steel block of width 40 mm is being milled using a straight stab cutter 70 mm diameter with 30 teeth. If the cutter rotates at 40 r.p.m. and depth of cut is 2 mm, what is the value of maximum uncut chip thickness when the table feed is 20 mm/min

1.  0.00263 mm

2.  0.00363 mm

3.  0.00463 mm

4.  0.00563 mm

4

0.00563 mm

Explanation :
No Explanation available for this question

# A cylindrical bar is to be turned. The maximum allowable feed is 0.2 mm/rev. And at this feed rate Tasla’s tool life equation for a tool-work combination is found to be VT0.25 = 75.Where V is the cutting speed in m/min and T is the corresponding tool life in minutes. The labour cost and overheads \$0.15 per minute and the total cost involved in each regrinding of the tool is \$ 2.5. on average, it takes about a minutes to change the tool. What is the cutting speed that will lead to the minimum cost

1.  22.4 m/min

2.  25.4 m/min

3.  27.4 m/min

4.  32.4 m/min

4

27.4 m/min

Explanation :
No Explanation available for this question

# A mild steel (ms) block of 20 mm width is being milled using a straight slab milling cutter with 20 teeth, 50 mm diameter, and 100 radial rakes. The feed velocity of the table is 15 mm/min and the cutter rotates at 60 r.p.m. If a depth of cut of 1 mm is used, what will be the power consumption (μ = 0.5, τ = 400 N/mm2 )

1.  30 W

2.  50 W

3.  60 W

4.  80 W

4

60 W

Explanation :
No Explanation available for this question

1.  68 N

2.  118 N

3.  136 N

4.  386 N

4