A taper 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
Correct Answer :
B. Its end tapered for about eight or ten threads
Related Questions
The tool material, for faster machining, should have
Wear resistance
Red hardness
Toughness
All of these
Which of the following statement is correct about nose radius?
It improves tool life
It improves the surface finish
Both (A) and (B)
None of these
The cutting fluid mostly used for machining alloy steels is
Water
Soluble oil
Dry
Sulphurised mineral oil
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
The snag grinding is done
To produce good surface finish and high degree of accuracy
To remove considerable amount of metal without regard to accuracy of the finished surface
To grind exterior cylindrical surfaces
Any one of the above
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 metal machining, the zone where the heat is generated due to friction between the moving chip and the tool face, is called
Friction zone
Work-tool contact zone
Shear zone
None of these
In Oxyacetylene gas welding, temperature at the inner cone of the flame is around
3500⁰C
3200⁰C
2900⁰C
2550⁰C
The guideways are of
Flat type
V-type
Dovetail type
Any one of these
Which of the following operations can be performed with milling cutters?
Cutting key ways on shafts
Cutting external screw threads
Cutting teeth of spur gears
All of these
For turning small taper on long workpiece, the suitable method is
By a form tool
By setting over the tail stock
By a taper turning attachment
By swivelling the compound rest
Two streams of liquid metal which are not hot enough to fuse properly result into a casting defect known as
Cold shut
Swell
Sand wash
Scab
The saw milling is an operation of
Producing grooves around the periphery of a cylindrical or conical workpiece
Producing narrow slots or grooves on a workpiece
Reproduction of an outline of a template on a workpiece
Machining several surfaces of a workpiece simultaneously
Misrun is a casting defect which occurs due to
Very high pouring temperature of the metal
Insufficient fluidity of the molten metal
Absorption of gases by the liquid metal
Improper alignment of the mould flasks
The correct sequence of tool materials in increasing order of their ability to retain their hot hardness is
Carbide, ceramic, cermet, borazon
Ceramic, carbide, borazon, cermet
Cermet, carbide, ceramic, borazon
Borazon, ceramic, carbide, cermet
Discontinuous chips are formed during machining of
Brittle metals
Ductile metals
Hard metals
Soft metals
The increase in depth of cut and feed rate __________ surface finish.
Improves
Deteriorates
Does not effect
None of these
Cast iron during machining produces
Continuous chips
Discontinuous chips
Continuous chips with built-up edge
None of these
For machining a mild steel workpiece using carbide tool, the maximum material will be removed at a temperature of
50°C
100°C
175°C
275°C
The specific cutting energy used for establishing the machinability of the metal depends upon its
Coefficient of friction
Microstructure
Work hardening characteristics
All of these
The capacity of a material to be welded under the imposed fabrication conditions into a specific, suitably designed structure and to perform satisfactorily in the intended service is known as?
Weldment
Weld tab
Weldability
Tack weld
Grinding wheels should be tested for balance
Only at the time of manufacture
Before starting the grinding operation
At the end of grinding operation
Occasionally
If the helix angle of the drill is made _________ 30°, then the torque required to drive the drill at a given feed will be more.
Equal to
Less than
More than
None of these
A lead-screw with half nuts in a lathe, free to rotate in both directions has
V-threads
Whitworth threads
Buttress threads
Acme threads
The example of snag grinding is
Trimming the surface left by sprues and risers on castings
Grinding the parting line left on castings
Removing flash on forgings
All of these
The size of abrasive grain required in a grinding wheel depends upon the
Amount of material to be removed
Hardness of material being ground
Finish desired
All of these
Gear finishing operation is called
Shaping
Milling
Hobbing
Burnishing
In a plain milling cutter, the portion of the gash adjacent to the cutting edge on which the chip impinges is called
Face
Fillet
Land
Lead
It is desired to perform the operations like drilling, reaming, counter-boring etc. on a work piece. Which of the following machine will be used?
Sensitive drilling machine
Radial drilling machine
Gang drilling machine
Multiple spindle drilling machine
In abrasive jet machining, as the distance between the nozzle tip and the work surface increases, the material removal rate
Increases continuously
Decreases continuously
Decreases, becomes stable and then increases.
Increases, becomes stable and then decreases.