All language subtitles for S07E10 - Firefighter Helmets; Nautical Compasses; Packaging Tubes; Hand Saws (576p AMZN WEB-DL x265 Garshasp)_track4_[eng]

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Narrator:
Today on "How it's made"...

Firefighter helmets.

Nautical compasses.

Packaging tubes.

And handsaws.

In the early 1800s,

Luggage maker henry gratacap

Created one
Of the first firefighter hats.

The leather helmet
Had a long rear brim

And curved sides as a shield
Against falling debris

And water running down the neck.

Except for a few
High-tech additions,

This basic design
Is still used today.

Leather is surprisingly
Flame-resistant.

When reinforced,

It also becomes
A remarkable hard hat,

Protecting from heat, liquids,
And sudden impact.

On this newer model,

The accessories
Shield the eyes and ears, too.

A helmet starts with four
Die-cut leather sections.

They sew them together

To make what's called
The skull of the helmet.

This piece will become
The brim of the helmet.

To give the skull structure,

A worker folds
And sews each section,

Then flattens the crease
With a special hammer.

He uses a template to score
A sewing line in the leather.

Then he uses
A powerful sewing machine

To join the sections together.

He now joins
The two halves together,

Reinforcing them
With double stitching.

The resulting eight ridges

Give the skull stiffness
And strength.

He stretches the leather
Over a plastic mold

And trims excess leather
From the ridges.

Then he clamps four vise grips
To the rim.

These attach to a hydraulic jack

That stretches
The skull overnight.

After applying glue
To the ridges,

He runs them through compression
Rollers for a tight bond.

They wet the brim piece
Several times

To make it more pliable.

Then they stamp it

With the design used
By this company since 1846.

But first,
A worker inserts a wire

That will give the brim
Some structural support,

Then a temporary plastic cover

And a lid to ensure
An even spread of pressure

Across the brim.

She stuffs the edges
Of the leather inside

Before the press applies 10 tons
Of force to imprint the design.

Next, a worker sews the skull
To the brim.

He removes the excess leather
At the base of the skull...

...And cuts out
The center of the brim.

Then he removes
The plastic mold.

To seal the leather,

They dip the hats in a vat
Of hot rosin,

A type of tree sap.

After 55 minutes,

They remove them
And let them dry

At room temperature
For eight weeks.

This slow-drying process

Makes the leather
About as hard as wood.

Drying it mechanically
Would make it brittle.

Now for the inside.

They insert a plastic cap
To reinforce the structure.

The fit is intentionally tight,

So they use a mallet
To tap it into place.

Inside that
They add another plastic cap

With nylon straps to resist
The impact of falling objects.

Here a worker uses
An acetylene torch

To burn off any loose threads
And soften the leather

In order to bend the brim

And straighten
The ridges later on.

Turning up the sides
Is basically for aesthetics,

But the longer edge in the back

Is to direct water
Away from the neck.

After adding a synthetic,
Fire-retardant liner,

He sands the outer surface
To prep it for painting.

First, a fire-retardant
Chemical primer.

Then they use
A semigloss latex paint

In firefighter's black or white
For the chief...

...Or, if you prefer,
A clear varnish

To show off the natural leather.

Add a front piece

With the firefighters'
Signature brass eagle on top

And some fluorescent stickers
For extra visibility,

And you've got
The right headgear

For a hero's job.

Narrator:
For more than 1,700 years,

The compass has been helping
People find their way.

It was first developed in china,

But when the far east
Met the far west,

European sailors
Adopted the technology,

Using it to chart
Their own courses.

To make a nautical compass,
They use this device

To magnetize
A special metal alloy.

A technician slips
A retainer ring onto a jig

And positions the magnet
On top of it.

She places an aluminum skirt
Over the magnet.

This will support the compass
Dial, which goes on next.

She inserts a pivot needle
In the center,

Which will allow the dial
To rotate.

Then she press-fits
All the pieces together.

She carefully inspects the fit,
And it looks solid.

She sprays a chemical cleaner
Into the pivot cavity.

It has to be spotless

Because any dirt
Would impede its function.

She also cleans
A little jewel post

That contains a tiny sapphire.

Then she fixes the jewel post
In the dial.

The jewel post
Will support the dial

While allowing the pivot needle
To move easily

As it's pulled
By magnetic forces.

She places the dial on a machine
That mimics the earth's pull.

It's a crucial step
Because magnetic force varies

Depending on where you are
In the world.

She brushes a weighted paint
Onto the back of the dial

To counteract the pull.

This balances the compass dial,

Preventing false readings
Due to differences

In the planet's magnetic force.

These are lubber lines --
Little direction markers.

She inserts them
Into holes in a jig.

Then she lines them up
With holes

In an aluminum gimbal pan

And press-fits the lubber lines
To the pan.

Now she inserts two pins
Into the gimbal ring

That allow the ring
To flip around the gimbal pan.

Then she attaches the compass
Dial to the gimbal assembly.

The technician spray-paints
The metal compass bowl black

And pops a rubber diaphragm
Into it.

A bronze ring
Will hold it in place.

This flexible rubber liner
Will contain the compass fluid

And allow it to expand
And contract.

She snaps the dial
And gimbal setup to the bowl.

She just has to bend
A little tab to level it out.

She positions
An acrylic dome on top.

Using another jig,

She puts a rubber o-ring
Over the dome to seal it,

Followed by a metal collar.

With a power screwdriver,

She anchors these pieces
To the rest of the compass.

Then she pumps fluid
Into the bowl,

Filling it right up
To the dome.

The fluid makes the numbers
On the dial look bigger.

Next, they magnetically charge
Two metal rods

And install them
In a compass base.

They'll compensate
For magnetic fields on the boat.

She mounts a big metal
Housing unit on the base.

Then she attaches
Shock absorbers

To cushion the compass
Against engine vibrations.

She installs the compass
In the housing

And taps the dome
To test the shocks.

A decorative aluminum cover
Fits around the dome.

Then she installs a light

To allow the navigator
To see at night.

She attaches iron spheres,

Another tactic to counter
Magnetic interference.

Our journey through the plan
Is now over,

And the compass
Is ready to be used.

Narrator: artists first used
Flexible metal containers

For their paints back in 1841.

Nowadays, we use them
For a range of things,

Like toothpaste, glue,
And skin cream.

The tube's design lets us
Squeeze out most of the product

And yet still read
That important fine print

On the twisted package.

These packaging tubes
Are made of aluminum

Because it's affordable,
Lightweight, and malleable.

This company makes each tube

From an aluminum slug
About the size of a coin.

A worker dumps a batch of slugs
In a container,

Then adds a lubricating powder
Called zinc stearate.

The container spins,

Causing the powder
To coat the slugs evenly

And prep the metal
For stretching later on.

The slugs then spin around
In another container,

Which orients them horizontally

So they'll fit through a channel
At the bottom.

The channel feeds the slugs
Into a forming press.

In a process
Called impact extrusion,

Each slug moves onto a die,

Which gives it the exterior
Shape of a tube,

Including the neck.

At the same time,
A mandrel forms the interior.

This process hardens the metal,

Something they'll correct
Later on by heating it.

The machine applies 200 tons
Of pressure

To as many as 150 slugs
Per minute.

They can be as narrow
As a half-inch

And as long as 8 1/2 inches.

This machine uses compressed air

To align the tubes
For the next step.

A trimming machine
Cuts threads into the necks

By passing each one between
Two synchronized rollers.

Stationary blades
Trim the top of the neck,

Making the surface smooth
And safe to handle.

The neck on most models
Remains sealed

Until the consumer pierces it.

Another company
Eventually seals the tube

By rolling up the other end

After they've inserted
Their product.

After heating them
To soften the metal,

The tubes move through
Another machine.

Here nozzles spray the inside
With two coats of epoxy lacquer.

This creates
A protective barrier

Between the aluminum
And the eventual contents.

Rollers apply a coat
Of polyester enamel paint,

Which is flexible when dry

And resistant to most solvents
And sun damage.

Grippers place the tubes
On long pins,

Which move them through an oven
For seven minutes

So the paint can dry.

From there, it's off
To the printing machine.

Each tube makes one
Complete rotation

Against a printing plate.

The plate applies
A colored image

And information that describes
The tube's contents.

Then they go back in the oven
To dry the ink.

The printing's legible
Even when twisted

Because the polyester ink
Remains flexible.

Another machine
Applies 2.2 pounds of torque

To screw on the plastic caps.

Most of the caps
Have pointy tops,

Used to pierce the sealed neck
Of the tube.

They use flat caps

To close off tubes
With open necks.

On the next machine,

Nozzles spray on a strip
Of latex sealant

Inside the open end of the tube.

The latex is like a gasket.

After the product is inserted,

It seals the tube
When they fold the end over.

After a machine packs boxes

With an average
Of 300 tubes each,

A worker inspects the inside
Of every tube.

A bright spotlight
Reveals any chip in the paint

That makes
The packaging deficient.

About one in every 500 tubes
Is flawed.

A sheet of sticky paper
Over the open ends of the tubes

Keeps them from twisting
During shipping,

And a label on the box
Provides tracking information

And a way to show if someone
Has tampered with it en route.

Empty, each tube sells
For about 12 cents each,

A great bargain
For such a useful item.

Narrator: even though it was
Invented thousands of years ago,

The handsaw is still used today.

You'll find it
At every building site,

Always at the ready.

Power tools are higher-tech,

But the handsaw
Has a basic appeal.

It doesn't need
An extension cord

And almost never breaks down.

It's a time-tested
Building tool.

Handsaws come in many sizes.

To make them,
A machine uncoils steel

And draws it
Into a mechanized punch.

The punch works
At a blurring speed

To cut teeth in the steel --
140 notches per minute.

Here it is in slow motion.

It makes two cuts
For each sawtooth.

A reel takes up
The newly serrated steel

And then will feed it back
To cut teeth on the other side.

Next, a fingerlike device
Unrolls the steel

And pushes it to automated jaws.

The jaws bend the teeth,

Alternating the direction
Of each one.

Here's a slow-motion look.

This is called
Setting the teeth,

And it will allow the handsaw
To operate smoothly.

Now a die punch
Cuts the steel coil

Into pieces
Called double blanks --

Double because two saw blades
Will be made from them.

The die also makes holes
In one end of the double blank

For attaching handles.

They feed the double blanks
To a sheer machine.

A long blade descends

And cuts it in half
On the diagonal,

Making two saw blades.

Finally, they press the saw
Blades up against a sand belt

To smooth out the edges.

This is called deburring.

Here they're making
A higher-end saw blade.

They flush a piece of steel
With coolant

As a machine plunge-grinds it
To make teeth.

This method
Is more time-consuming

But results in a superior tool.

Again, they set the teeth,

But this time, mechanical jaws
Do the job a blade at a time,

Rather than working
On one long coil of steel.

The sawteeth will need
To be strengthened

In order to perform,

So rollers move the blades
To an electrical coil.

Within milliseconds,
The temperature of the blade

Shoots up
To 1,600 degrees fahrenheit.

This tempers the steel.

The blades drop off
The conveyer into a bin.

Here's a look at a blade
Before heat-treating.

And this is after.

The black burn line is a sign
This saw can take the pressure.

A conveyer wheel dunks them
In a pool of clear protectant.

This will keep them
Looking shiny.

When they're dry,

The blades undergo
A trademark technique.

They place one on a table.

It rises and a squeegee
Silk-screens the company name

Onto it.

At this point,
The ink is still wet.

They spend 30 seconds
In an infrared oven --

Enough time
To bake on the brand name.

They slide cardboard sleeves
Over the blades,

And now it's time
To attach the handle.

A worker fits two
Plastic parts together

And places them on a carousel.

An ultrasonic sealer moves in.

It emits a high-frequency sound,

And the vibrations melt
The two plastic pieces together,

Forming a handle.

A worker fits the handle
Onto a blade,

And a machine rivets it
In place.

Some saws have wooden handles.

Because riveting
Could split the wood,

They bolt it on
With screws and rivnuts.

And now you have
The finished product.

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About the show,

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Topics for future shows,

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