Part B Exam - Unit 5

Hacksaws cut through all metals except:

Hardened steel

Which hacksaw teeth are used for thin stock and which are used for thick stock?

Fine teeth for thin, coarse teeth for thick

What hacksaw blade is hard, long-wearing, and straight-cutting?

Molybdenum blades

What hacksaw blade cuts the toughest materials?

Tungsten blades

What hacksaw blade only has the teeth hardened?

Flexible blades

How many strokes per minute is recommended for a hacksaw?

40

When using a hacksaw, at least \____ teeth should be cutting at a time.

3

How many strokes per minute is recommended for a file?

30 to 40

What does "pinning" refer to when using files?

When small particles of metal become clogged in the teeth

For a heavy rough cut, use:

Coarse, double cut

For finishing cuts, use:

Second cut
Smooth, single cut

For cast iron, use:

Bastard cut, finishing with a smooth cut

For soft steel, use:

Second cut, finishing with a smooth cut

For hard steel, use:

Smooth cut, finishing with a dead smooth cut

For brass or bronze, use:

Bastard cut, finishing with a second or smooth cut

What is the simplest type of cutting tool?

Chisels

What are the four types of chisels?

Cold, cape, round nose, diamond point

While grinding, what should you do with the chisel?

Dip chisel in water

Chisel cutting angle is generally:

60° to 70°

What tool is most commonly used when working with metal-cutting chisels?

A 1 kg hammer

Shear chisel cutting may be accomplished on steep up to \____ mm thick.

3

Why is the face of the hammer rounded a little?

So the force of the blow is concentrated in the centre

It is not advisable to use a hammer to:

Drive nails

The outer jaw of the pipe wrench is adjustable by means of a:

Knurled nut

Which wrench should not be used on finished surfaces?

Pipe wrenches

How does the ratchet drive in the socket wrench speed up the work?

Because the socket does not need to be removed from the nut/bolt after each turn

Which tap is used for general use?

Plug tap

Which tap is used to start a thread easily, go through the workpiece, or start a blind hole?

Taper tap

Which tap is used to finish any hole started by the taper tap?

Bottoming tap

Which die recuts battered thread and is not adjustable?

Solid die

Which die permits a certain amount of adjustment?

Round split die

Which die is the most efficient?

Adjustable die

What angle should you use a prick punch? What about for a centre punch?

60° for prick punch, 90° for centre punch

What are portable grinders normally equipped with?

Wheel guards and spindle friction clamping assembly

What is the purpose of the spindle friction clamping assembly?

It applies pressure to the grinding wheel to hold it tightly against the flanged end

What is the fixed grinder equipped with for safety?

Spindle friction clamping assembly

The fixed grinder consists of a \_____________ motor.

Double-ended sealed

Abrasive wheels are classified and marked using six different categories:

Abrasive type

Grain size

Grade

Structure

Bond type

Manufacturer's record

What is the aluminum oxide abrasion used for?

General purposes

What is the silicon carbide abrasion used for?

Very hard metals and tool bits

Structure of the abrasive wheel refers to a range of grains from the __________ to __________.

Dense type

Open type

What are the four different bond types in abrasive wheels?

Vitrified, resinoid, rubber, shellac

Which abrasive bond the most common?

Vitrified

The vitrified bond type uses a \__________-type material to bond.

Ceramic

What happens if the hand drill bit slips?

Its shank will become burred

What are the most common types of drill presses?

The shop bench and floor/pedestal-mounted type

What differentiates the shop bench and the floor/pedestal-mounted type drill press?

Their height and mounting

What are twist drill bits made from?

Carbon steel or high-speed steel

Why is it better to use high-speed steel than carbon steel for the twist drill bits?

Because the cutting edge lasts longer

Bits up to \_____ mm tend to have straight shanks; larger ones have tapered shanks.

12

Straight bits are held in the ________, while tapered bits fit into the ________.

Drill chuck

Internal taper

Why does the tapered shank have a tang on the end?

To prevent the bit from slipping

The point angle used for drilling is usually:

118°

If a hole to be drilled is over 10 mm:

A pilot hole should be drilled first

What happens if the drilling speed is too slow?

The bit may break

What happens if the drilling speed is too fast?

The cutting edges will dull rapidly

Why may work surfaces have built-in cleats?

To prevent planks from slipping off the scaffold frame

What knowledge is required to perform rigging operations safely? (4)

Construction of the object

Path of the move

Materials and equipment available

Safety requirements

Where are chain hoists and come-alongs used?

Where a load must be lifted and held suspended for an extended timeframe

Chain hoists are used for \________ lifting.

Vertical

The MA of chain hoists and come-alongs is quite high, so it may be difficult to:

Tell when the device is overloaded, just by feeling it

Whenever two or more sling eyes are used for chain hoists/come-alongs, they should be held in:

A shackle with a screw-in pin

Which is the most common type of rope?

Wire rope

What materials may wire rope be made of?

Steel, or a combination of steel and natural fibre

Rope with more wires is:

More flexible, but less resistance to corrosion

What is the purpose of hemp in the wire rope?

To act as a cushion and storage space

Why are some wire rope clips made with bronze?

For electrolysis or corrosion

Why should eyes in a wire rope always have a thimble installed?

To reduce strain and wear on the rope

What materials are fibre ropes made of?

Manila, hemp, and cotton

To make sure you don't overload a fibre rope, use a factor of safety of:

5

What materials are synthetic ropes made of?

Nylon, Dacron, saran, and polyethylene

Which synthetic ropes are highly resistant to acids, alkalis, and common solvents?

Saran and polyethylene ropes

In what situations is the nylon rope used?

Where shock loading is common, or when a rope smaller than natural fibre is needed

The nylon rope is resistant to oil and greases, but affected by:

Paint and acids

Dacron ropes are resistant to:

Mildew, rot, and abrasives

What properties do Dacron ropes have compared to nylon ropes?

Has less elasticity than nylon, but is more resistant to acid and water

The Dacron rope is characterized by its:

Greater tensile strength

Which synthetic ropes are unaffected by water?

Saran and polyethylene ropes

The saran rope cannot be used at temperatures greater than \____degC.

50

What's the difference between saran ropes and polyethylene ropes?

Saran ropes have high resistance to abrasion, while polyethylene ropes have poor resistance to abrasion

The polyethylene rope is unaffected by:

Mildew, rot, and fungi

When are suspending type eye bolts used?

When there is no possibility of using a sling

What is the preferred method of raising the chain falls?

A hand line supported separately but close to the eye bolt

Eye bolt strain can be loaded up to 45° if \____________ are used.

Shoulder eye bolts

What shape do stove bolts usually resemble?

Square

What shape do carriage bolts usually resemble?

Truss or square

What shape do machine bolts usually resemble?

Hexagon

Machine screws are similar to stove bolts, except:

They usually have the threads running along their full length

What shape do nuts and bolts resemble?

Square or hexagon

What are carriage bolts usually used for?

Fastening wooden parts to metal parts

What kind of holes are stove bolts used in?

Tapped holes or holes with nuts on the end

Machine bolts are used where:

A snug fit is required

Cap screws have to have a _________ under the head and a _________.

Washer face

Chamfered point

What material are cap screws made of?

Low-carbon steel

What are set screws used for?

Assembling shafts to pulleys, or hold parts in a fixed position to each other

When equipment is dismantled, the stud:

Remains in place

What are studs made from?

Cylindrical stock threaded at both ends

What are studs used for?

Fastening pipe flanges together

What is the most common type of threaded fastener?

Bolts

Which mechanical fastener is case-hardened and able to withstand severe use?

Set screws