Before operating a pneumatic tool, inspect
the air hose and check it for leaks or damage.
Blow air through the air hose to free it of foreign
material before connecting it to the tool. Keep
the air hose clean and free from lubricants.
Never point the air hose at another person.
Pneumatic tools must have complete lubrication.
The moving parts of pneumatic tools are fitted very
closely, and they must be lubricated correctly or they
will wear quickly and fail to work.
Valves and pistons on pneumatic hammers require
a light machine oil. Since the compressed air comes
directly in contact with these parts, it has a tendency
to drive the lubricant out through the exhaust.
When working continuously with a pneumatic
tool, you should regularly check the lubricator to
ensure there is ample lubricant available. Next, empty
the filter assembly as needed.
On low-pressure compressed air systems that do
not have the filter, the regulator, and the lubricator
assembly installed, you should disconnect the air hose
every hour or so and squirt a few drops of light oil into
the air hose connection. Do NOT use heavy oil
because the oil will cause precision parts to either fail
or to have operating troubles. If this occurs, you have
to clean your tool in cleaning solvent to loosen the
gummy substance that results. Blow out the tool with
air, lubricate it with light oil, and go back to work.
Keep your pneumatic tools clean and lubricated
and you will have few operating problems.
Prefabrication of steel parts and assemblies is
typically accomplished in a steel shop where heavy
steel working machinery is accessible. The steel shop
is tasked with manufacturing and fabricating items,
such as sheet-metal ducts, pipeline section fittings,
plates, and angles. In the following sections, we will
discuss some of the common types of machinery found
in a well-equipped steel shop.
COMBINATION IRON WORKER
The combination iron worker is likely the most
valuable and versatile machine in a shop. The
combination punch, shear, and coper (fig. 12-8) is
capable of cutting angles, plates, and steel bars, and it
can also punch holes. The size of the angles and plates
that can be safely handled by the machine depends
upon its capacity. It is manufactured in various sizes
and capacities, and each machine has a capacity plate
either welded or riveted on it. This guide should be
strictly adhered to. The pressure and power the
machine develops demand extreme caution on the part
of the operator.
VERTICAL BAND SAWS
While the vertical band saw is designed primarily
for making curved cuts, it can also be used for straight
cutting. Unlike the circular saw, the band saw is
frequently used for freehand cutting.
The band saw has two large wheels on which a
continuous narrow saw blade, or BAND, turns, just as
a belt is turned on pulleys. The LOWER WHEEL,
located below the WORKING TABLE, is connected
to the motor directly or by means of pulleys or gears
and serves as the driver pulley. The UPPER WHEEL
is the driven pulley.
The saw blade is guided and kept in line by two
sets of BLADE GUIDES: one fixed set below the
table and one set above with a vertical sliding
adjustment. The alignment of the blade is adjusted by
a mechanism on the back side of the upper wheel.
TENSIONING of the bladetightening and
loosening-is provided by another adjustment located
just back of the upper wheel.
Cutoff gauges and ripping fences are sometimes
provided for use with band saws. However, you will
do most of your work freehand with the table clear
because accurate cuts are difficult to make with a band
saw when gauges or fences are used.
The size of a band saw is designated by the
diameter of the wheels. Thus the 14-inch model (fig.
12-9) has 14-inch wheels. Common sizes are 14-, 16-,
20-, 30-, 36-, 42-, and 48-inch machines. The
14-inch size is the smallest practical band saw. With
the exception of capacity, all band saws are much alike
in maintenance, operation, and adjustment.
Blades, or bands, for bandsaws are designated by
POINTS (tooth point per inch), THICKNESS (gauge),
and WIDTH. The required length of the blade is found
by adding the circumference of one wheel to twice the
distance between the wheel centers. Length can vary
within a limit of twice the tension adjustment range.
Vertical band saws are comparatively simple
machines to operate. Each manufacturer publishes a
technical manual for their machine. Refer to the