The helix angle of a drill is __________ for drilling brass.
Equal to 30°
Less than 30°
More than 30°
None of these
Correct Answer :
B. Less than 30°
Related Questions
In drilling aluminium, a drill with
Zero helix angle is used
Low helix angle is used
High helix angle is used
Any helix angle can be used
While cutting helical gears on a non-differential gear hobber, the feed change gear ratio is
Independent of index change gear ratio
Dependent on speed change gear ratio
Interrelated to index change gear ratio
Independent of speed and index change gear ratio
The height of each tooth of a broach is
Same throughout
In progressively decreasing order
In progressively increasing order
None of these
The abrasive recommended for grinding materials of high tensile strength is
Silicon carbide
Aluminium oxide
Sand stone
Diamond
In a single point tool, the angle between the surface of the flank immediately below the point and a line drawn from the point perpendicular to the base, is known as
Side relief angle
End relief angle
Back rake angle
Side rake angle
In electro discharge machining, tool is made of
Brass
Copper
Copper tungsten alloy
All of these
The tail stock set over method of taper turning is preferred for
Internal tapers
Small tapers
Long slender tapers
Steep tapers
Broaching is applied for machining
Internal and external surfaces
Round or irregular shaped holes
External flat and contoured surfaces
All of these
The swing diameter over the bed is ________ the height of the centre measured from the bed of the lathe.
Equal to
Twice
Thrice
One-half
The method of centre less grinding used to produce taper is
In-feed grinding
Through feed grinding
End feed grinding
Any one of these
What is the type of joining process called, where the parts to be welded are kept in contact and rotated relative to each other and axial pressure is applied when the desired temperature is obtained?
Ultrasonic welding
Forge welding
Electron beam welding
Friction welding
A twist drill is specified by its
Shank, material and diameter
Shank, lip angle and size of flute
Material, length of body and helix angle
Any one of these
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
A right hand tool on a lathe cuts most efficiently when it travels
From left to right end of the lathe bed
From right to left end of the lathe bed
With the help of a compound slide
Across the bed
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
A drill bit of 20 mm diameter rotating at 500 r.p.m. with a feed rate of 0.2 mm/revolution is used to drill a through hole in a mild steel plate 20 mm thickness. The depth of cut in this drilling operation is
0.2 mm
10 mm
20 mm
100 mm
A drill mainly used in drilling brass, copper or softer materials, is
Flat drill
Straight fluted drill
Parallel shank twist drill
Tapered shank twist drill
In order to prevent tool from rubbing the work _________ on tools are provided.
Rake angles
Relief angles
Face angles
None of these
Internal or external threads of different pitches can be produced by
Pantograph milling machine
Profiling machine
Planetary milling machine
Piano miller
The factor considered for evaluation of machinability is
Cutting forces and power consumption
Tool life
Type of chips and shear angle
All of these
Tumbler gears in lathe are used to
Reduce the spindle speed
Cut gears
Give desired direction of movement to the lathe carriage
Drill a workpiece
In ECM, the material removal is due to
Corrosion
Erosion
Fusion
Ion displacement
The cutting force in punching and blanking operations mainly depends on
The modulus of elasticity of metal
The shear strength of metal
The bulk modulus of metal
The yield strength of metal
The carbide tools operating at very low cutting speeds (below 30 m/min)
Reduces tool life
Increases tool life
Have no effect on tool life
Spoils the work piece
In machining metals, surface roughness is due to
Feed marks or ridges left by the cutting tool
Fragment of built-up edge on the machined surface
Cutting tool vibrations
All of these
The object of caulking in a riveted joint is to make the joint
Free from corrosion
Stronger in tension
Free from stresses
Leak-proof
In oblique cutting system, the cutting edge of the tool
May clear the width of the workpiece
May or may not clear the width of the workpiece
May not clear the width of the workpiece
Should always clear the width of the workpiece
A grinding wheel becomes glazed (i.e. cutting edge takes a glasslike appearance) due to
Wear of bond
Breaking of abrasive grains
Wear of abrasive grains
Cracks on grinding wheel
The rake angle required to machine brass by high speed steel tool is
0°
10°
20°
100°
Lapping is an operation of
Making a cone-shaped enlargement of the end of a hole
Smoothing and squaring the surface around a hole
Sizing and finishing a small diameter hole
Producing a hole by removing metal along the circumference of a hollow cutting tool