Materials Science and Manufacturing Engineering Miscellaneous
- In an engineering drawing one finds the designation of 20G7f8, the position of tolerance of the hole is indicated by
-
View Hint View Answer Discuss in Forum
Capital letter for Hole → G
Small letter for shaft → f
7 for → IT7
8 for → IT8
IT → Tolerance zone widthCorrect Option: A
Capital letter for Hole → G
Small letter for shaft → f
7 for → IT7
8 for → IT8
IT → Tolerance zone width
- The hole 40+0.020 +0.000 and shaft, 40+0.010 +0.000 when assembled will result in
-
View Hint View Answer Discuss in Forum
Correct Option: C
Direction: A disc of 200 mm outer and 80 mm inner diameter is faced at a feed of 0.1 mm/rev with a depth of cut of 1 mm. The facing operation is undertaken at a constant cutting speed of 90 m/min in a CNC lathe. The main (tangential) cutting force is 200 N.
- Neglecting the contribution of the feed force towards cutting power, the specific cutting energy in J/mm3 is
-
View Hint View Answer Discuss in Forum
Specific cutting energy (SCE) = FC = 200 = 2 J / mm3 d × f 0.1 × 1 × 1000 Correct Option: B
Specific cutting energy (SCE) = FC = 200 = 2 J / mm3 d × f 0.1 × 1 × 1000
- Two cutting tools are being compared for a machining operation. The tool life equations are
Carbide tool VT1.6 = 3000
HSS tool VT0.6 = 200
where V is the cutting speed in m/min and T is the tool life in min. The carbide tool will provide higher tool life if the cutting speed in m/min exceeds
-
View Hint View Answer Discuss in Forum
Carbide tool: VT1.6 = 3000
HSS tool: VT 0.6 = 200T = 3000 1 /1.6 V T = 200 1 /0.6 V T = 3000 1 /1.6 = 200 1 /0.6 V V
V = 39.389 m/minCorrect Option: B
Carbide tool: VT1.6 = 3000
HSS tool: VT 0.6 = 200T = 3000 1 /1.6 V T = 200 1 /0.6 V T = 3000 1 /1.6 = 200 1 /0.6 V V
V = 39.389 m/min
- Assuming approach and over-travel of the cutting tool to be zero, the machining time in min is
-
View Hint View Answer Discuss in Forum
t = π( d02 - d12 ) = π[ (0.2)2 - (0.08)2 ] 4.fr.V 4 × 0.1 × 10-3 × 90
time, t = 2.93 minutesCorrect Option: A
t = π( d02 - d12 ) = π[ (0.2)2 - (0.08)2 ] 4.fr.V 4 × 0.1 × 10-3 × 90
time, t = 2.93 minutes