A lead-screw with half nuts in a lathe, free to rotate in both directions has
V-threads
Whitworth threads
Buttress threads
Acme threads
Correct Answer :
D. Acme threads
Related Questions
Larger end cutting edge angle _________ tool life.
Increases
Decreases
Does not effect
None of these
Calculate the weld per minute, work speed of circular electrode of 220 mm diameter for carrying out seam welding at 4 welds per cm on 1.6 mm thick mild steel tube. Welding cycle consists of 3 cycles on and 2 cycles off Power supply is at 50 Hz.
3000 welds / min, 75 mm / min
600 welds / min, 1500 mm / min
500 welds/ min, 1250 mm/min
22 welds / min, 55 mm / min
In which of the following machine, the work is usually rotated while the drill is fed into work?
Sensitive drilling machine
Radial drilling machine
Gang drilling machine
Deep hole drilling machine
If the tearing efficiency of a riveted joint is 50%, then ratio of rivet hole diameter to the pitch of rivets is
0.20
0.30
0.50
0.60
When the shear angle is large
Path of shear is short and chip is thin
Path of shear is large and chip is thick
Path of shear is short and chip is thick
Path of shear is large and chip is thin
Side rake angle of a single point cutting tool is the angle
By which the face of the tool is inclined towards back
By which the face of the tool is inclined sideways
Between the surface of the flank immediately below the point and a plane at right angles to the centre line of the point of the tool
Between the surface of the flank immediately below the point and a line drawn from the point perpendicular to the base
The actual feed in centerless grinders is given by (where d = Dia. of regulating wheel, n = Revolutions per minute, and α = Angle of inclination of wheel)
πd
πdn
πdn sinα
πdn cosα
Crater wear is mainly due to the phenomenon known as
Adhesion of metals
Oxidation of metals
Diffusion of metals
All of these
An open structure of a grinding wheel is used for
Soft materials
Tough materials
Ductile materials
All of these
Which of the following statement is correct about hot machining?
It requires less power than machining metals at room temperature.
The rate of tool wear is lower.
It is used for machining high strength and high temperature resistant materials.
All of the above
In a CNC program block, N002 GO2 G91 X40 Z40......, GO2 and G91 refer to
Circular interpolation in counter clockwise direction and incremental dimension
Circular interpolation in counter clockwise direction and absolute dimension
Circular interpolation in clockwise direction and incremental dimension
Circular interpolation in clockwise direction and absolute dimension
While current is shut down in the welding circuit, what kind of voltage exists between the output terminals of the welding machine?
GTAW
Open air cut voltage
Kerf
Gouging
The structure of a grinding wheel depends upon
Hardness of the material being ground
Nature of the grinding operation
Finish required
All of these
A better machinable metal is one which gives
Lower chip-tool contact area and larger shear angle
Higher chip-tool contact area and smaller shear angle
Lower chip-tool contact area and smaller shear angle
Higher chip-tool contact area and larger shear angle
In an interchangeable assembly, shafts of size 25.000 -0.0100⁺⁰⁰⁴⁰ mm mate with holes of size 25.000 -0.010⁺⁰⁰²⁰ mm. The maximum possible clearance in the assembly will be
10 microns
20 microns
30 microns
60 microns
The main purpose of a boring operation, as compared to drilling, is to
Drill a hole
Finish the drilled hole
Correct the hole
Enlarge the existing hole
Crack in grinding wheel is developed due to
High temperature developed at the contact of the wheel face and work
Grinding hard work
Low speed of wheel
High speed of wheel
In order to obtain a surface finish in the range of 0.75 μm to 1.25 μm , the operation used is called.
Grinding
Lapping
Honing
Buffing
Which of the following operations is carried out at a minimum cutting velocity if the machines are equally rigid and the tool work materials are the same?
Turning
Grinding
Boring
Milling
The cutting speed of a drill depends upon the
Material of drill
Type of material to be drilled
Quality of surface finish desired
All of these
The trade name of a nonferrous cast alloy composed of cobalt, chromium and tungsten is called
Ceramic
Stellite
Diamond
Cemented carbide
In a metal arc welding process, a gas metal arc welding with magnetized flux is used and can be done in all the positions i.e. flat position, vertical position or inclined position.
Globular transfer
Spray transfer
GMAW practice
Dip transfer
The tailstock set over required to turn a taper on the entire length of a workpiece having diameters D and d is
(D - d)/2L
(D - d)/L
(D - d)/2
D - d
In up milling, the thickness of chip is
Minimum at the beginning of the cut and maximum at the end of the cut
Maximum at the beginning of the cut and minimum at the end of the cut
Uniform throughout the cut
None of these
The angle between the face and flank of the single point cutting tool is known as
Rake angle
Clearance angle
Lip angle
Point angle
The cutting speed for drilling __________ with high speed steel drills is 24 to 45 m/min.
Mild steel
Copper
Aluminium
Brass
The chuck used for setting up of heavy and irregular shaped work should be
Four jaw independent chuck
Three jaw universal chuck
Magnetic chuck
Drill chuck
A bottoming tap has
Its end tapered for about three or four threads
Its end tapered for about eight or ten threads
Full threads for the whole of its length
None of the above
An expendable pattern is used in
Slush casting
Squeeze casting
Centrifugal casting
Investment casting
The factor responsible for the formation of continuous chips with built up edge is
Low cutting speed and large rake angle
Low cutting speed and small rake angle
High cutting speed and large rake angle
High cutting speed and small rake angle