Metals are so useful that we need to know more about them and
the tools that are used to shape, cut, form, and finish them. The
following are the basic tools and equipment used in doing
metalworks:
1. Straightedge. A steel rule used to test the flatness of a
workpiece. The edge of the steel rule is placed on the surface of a
material and then held up against the light.
2. Outside caliper. This is used to measure the outside
dimensions of either a flat or round stock. It may also be used to
check the parallelism of surfaces. The setting on the outside
caliper may be converted into linear units by measuring the opening
with a steel rule.
3. Inside caliper. This is used to measure the diameter of holes
or widths of keyways and slots. To convert the inside caliper's
opening into linear units, use a steel rule in the same manner as
that of the outside caliper.
4. Hermaphrodite caliper. This consists of two legs, one is like
that of a divider and the other one is like the leg of an inside
caliper. Hermaphrodite calipers may be used to scribe arcs or in
marking layout work.
5. Try-square. This consists of a thick beam sometimes called
the stock and a thin blade set at 90° angle. This tool is commonly
used to test or "try" the accuracy of work. Many try-squares are
gradated on the blade so it may also be used as a rule.
6. Divider. This is similar in construction to calipers except
that the legs are straight and terminates in sharp points. These
are used for measuring distances between points, transferring
measurement from a scale, and scribing circles and arc.s
7. Tape rule. This comes in different lengths but commonly in
two metre lengths. They are useful in measuring large dimensions
such as lengths of metal bars and width of iron sheets. The
flexible metal tape rule is housed into a small metal receptacle
and can be pulled out when needed.
8. Vernier caliper. This is a device which measures dimensions
more accurately than most other measuring tools and is commonly
used in machine shop work.
9. Micrometer. This is used to measure very small dimensions. It
may be used to determine the thickness of a a shim or the diameter
of a single hair strand.
10. Layout table. This is actually made of granite or cast iron.
Granites are considered better than cast iron but are very
expensive. For very simple layout work, any plain surface such as
an ordinary table top will do.
11. Scribers. These are generally used with a straight edge rule
to draw straight lines. These are made of hardened steel and
sharpened to a very sharp point. On some scribers, one end is bent
to allow marking line in hard-to-reach places.
12. Layout punch. Also commonly known as prick punch. It looks a
center punch except that the point is ground to an angle of 30° to
60° and is used to permanently mark the location of layout
lines.
13. Center punch. Is practically the same as the prick punch
except that the point is ground to an angle of 90°. It is used to
mark the location of the centers of holes. The wider the angle of
indentation permits a drill bit to start holes accurately.
14. Bench vise. This is the most commonly used tool in benchwork
to securel hold small work for sawing, chipping, drilling, reaming,
polishing, and tapping operations. Vises are made of heavy cast
iron or cast steel. Their sizes are determined by the width of the
jaws. When gripping highly polished work or soft materials, jaw
caps are used to prevent the work surface from getting marred or
damaged. Jaw caps are made of plastic, lead, aluminum, or
copper.
15. Hammer. The most commonly used in benchwork are the ballpen,
straight peen, and crosspeen hammers. Aside form the three,
soft-faced hammers are also extensively used in metalwork. These
are used in assembling or disassembling parts so the finished
surfaces would not be dented. The faces of soft hammers are made of
lead, plastic, rawhide, wood, or copper. These are attached to a
steel handle and are generally replaceable.
16. Screwdriver. Instruments designed to drive in and take out
screws. The two most common types used in the shop are the standard
screwdrivers with a flat blade, and the Philips screwdriver with
the crossed tip to fit the recessess of a Philip-head screw. Both
of these types are manufactured in various sizes and styles such as
the standard, stubby, and offset. An important rule to remember in
the use of screwdrivers is to use the right size for the right
screw. Too big a size damages the slot of the screw and may even
cause the screw to break. Too small a size will dent the
screwdriver and also damage the slot of Philips screws.
17. Wrench. Different types of wrenches are used for specific
purposes. The name of a wrench is generally derived from its use,
shape, or construction. The more common types are as follows:
a. Open end wrench. May be single-ended or double-ended. The
opening is generally offset at 150° to permit turning the nut or
bolt in a crowded space by flooping or inverting the wrench every
single stroke. The double-ended wrench is usually of two opening
sizes to accomodate two bolt heads or nut sizes.
b. Box wrench. Is also called the box-end 12 point wrench. This
wrench completely surrounds the nut and has 12 equally spaced
notches inside. A small rotation of a nut can be affected by
shifting the wrench to another notch. It can move as little as 1/12
of a circle or 30°.
c. Socket wrench. Similar to the box wrench but is driven
differently by means of a handle provided with a square head which
fits on the top end of the socket wrench. The handles may be a
rachet or when certain bolts or nuts have to be tightened to a
correct degree, a torque handle is used.
d. Adjustable wrench. This has an opening which may be adjusted
within a certain range to fit several sizes of nuts or bolt heads.
This is particularly useful to repairmen who travel to do servicing
jobs, eliminating the need to carry too heavy a load of wrenches.
For shopwork, however, this type is not preferable since slippage
is more likely to happen if proper adjustments to the bolt head is
not attained.
e. Allen wrenches. These are hexagonal L-shaped rods that fit
into the slots of allen set screws.
18. Pliers. Are designed for gripping and holding small parts
for certain machining operations. They are also modified levers so
one can "multiply" gripping pressure with the use of these tools.
The different types of pliers are:
a. Slip-joint pliers. Are designed to grip small and big stocks
by simply slipping the fulcrum.
b. Side-cutting pliers. These are used mainly for gripping,
bending, and cutting small diameter rods or wire. When this pliers
is provided with insulated handles, it is also called the
electrician's pliers.
c. Long-nose pliers. These are manufactured either straight or
bent. They are usedd for holding very small parts and for
positioning in hard-to-get-at places. They are also very useful in
making small loops or rings out of wires. This is sometimes called
needle-nose pliers. The bent kind is also known as crooked-nose
pliers.
d. Diagonal-cutting pliers. Or simply diagonals are useful in
cutting, picking up, or putting cotter pins.
e. Vise grip pliers. Provide an extremely strong grip because of
the adjustable lever action. The grip pliers can be locked.
19. File. Is a hand cutting tool made of high carboon steel
having a series of teeth cut on a flat body or face. The parts of a
file are as shown below. Files without handles should not be used.
Files are classified according to how the teeth are cut on the
face. They may be single cut or double cut. According to the
coarseness or size of the cut they are classified as: rough,
coarse, bastard, second cut, smooth cut, and dead smooth. According
to cross sectional shapes, files are classified as: flat,
half-round, square, three-square (triangle), and knife.
20. Hacksaw. This is used in cutting metals and other materials
like fiber and plastics. It is composed of a handle, a frame, and a
blade.
21. Scraper. This is used to produce a surface more true that
can be produced by machining. Scraping is a process of removing
small amounts of metal from specific areas to produce an accurate
surface. It is a long and tedious process. Scrapers are made of
high grade hardened, and tempered tool steel. Carbides are
sometimes added to the tips to make them last longer.
22. Chisel. Is the simplest form of cutting tool. It is made of
heat-treated steel with the cutting edge shaped differently for
various chipping requirements. The following are the most commonly
used chisels in the metalworks shop:
a. Flat chisel. Is used for cutting and chipping metals and for
splitting nuts, bolt heads, and rivets. The blade of the flat
chisel is ground to an angle of 60° to 70°.
b. Diamond-point chisel. Is used for clearing out corners or
correcting errors while drilling in steel plates. It is ground to a
square cross section end and provided with a cutting edge at one
corner.
c. Cape chisel. Has a narrow cutting edge and is used in cutting
narrow grooves, splints, or keyways.
d. Round nose chisel. The tip of this chisel is round and is
used in making half round grooves and channels. It may also be used
for moving holes which have been inaccurately started.
These are called cold chisels because they are designed to cut
metals at room temperature. There are special chisels described as
hot chisels which are used to cut or chip while the metal being
worked on is red hot. These chisels are provided with a long handle
to keep the operator's hand away from the hot metal.
23. Snips. Are tools necessary in the metalworks shop especially
when working with metal sheets that are very thin (1/16 of an inch
thick). The snips are generally called tinner snips as these are
the main tools of a tinsmith. The different types of snips are:
a. Straight snip. Is used in cutting along a straight line on a
metal sheet, plastic, rubber, and other materials. They are made in
various sizes with cutting edges from two to five inches long. The
handles are generally plastic coated.
b. Hawk-bill snip. Has narrow, slightly curved blades. It may
also be used to cut a straight edge but is most effective in
cutting along inside curves.
c. Aviation snip. Has short cutting blades and two fulcrums for
a greater mechanical advantage. It may be used for cutting straight
edges or curves but is most effective in cutting long outside
curves.
24. Hand drills. Are tools used for drilling small holes through
metals, wood, or plastic. It consists of a shank which is attached
to a toothed wheel with a handle. The toothed wheel or gear turns
another toothed wheel and carries the shaft which holds the chuck
and the drill bit.
25. Twist drill. This is a cutting tool consisting of a steel
rod with two flutes running around its body, the point of which is
ground so that cutting edges are formed. Twist drills are
manufactured from forged steel. They are available in available in
a variety of sizes from a small as 1/32 to as big as two inches in
diameter. They are made with neither a straight or tapered shanks.
Small twist drills are generally straight while the bigger ones
tapered.
26. Reamer. Is made of special steel with shallow cutting edges
around its entire length. It is used to smoothen the surface of the
hole made by a drill to finish it to a standard size.