Here are
tips and suggestions to help you do a better job when using common fasteners like
screws and nails. Although there is nothing complex about a nail or a screw, many
are misused.
Selecting the Proper
Nail and Using it Correctly
Selecting
the Correct Screw and Using it Properly
FIG.
1 - Common nails FIG.
2 - Casing nails FIG.
3 - Finishing nails
FIG.
4 - Common brads FIG.
6 - As a rule of thumb, the nail should always be about three times as long
as the thickness of wood through which it is driven. FIG.
7 - How to countersink a nail. FIG.
8 - Nailing tips: (A) nails can be concealed in a piece of wood; (B) bend
nails over at the end for a strong joint; (C) never drive two nails in the same
grain of wood; (D) an upright can be toe-nailed to a flat surface.
FIG.
9 - Special nail for holding wallboard. FIG.
10 - Special fasteners: (A) nail for holding wood to concrete; (B) ring nail
for special holding power; (C) corrugated fasteners for corners; (D) upholstery
nails for fastening material to wood.
SELECTING THE PROPER NAIL AND USING IT CORRECTLY
Although there are many different
types of nails and brads, four types will handle most fastening jobs.
The common nail is most widely used (Fig.
1). It has a flat head and is used where the appearance of the nail head is not
objectionable.
The length of
a nail is identified by its "penny" size. In the early days of nail
manufacturing, this term designated the weight of nails per hundred. Today it
designates only the length and size of the nail.
The
designation 2d, 3d, 4d, etc., identifies a 2-penny, 3-penny, 4-penny nail, etc.
The casing nail is used primarily
on cabinet work or interior trim (Fig. 2). Casing nails are slightly heavier than
finish nails.
The heads of casing
nails are normally countersunk and covered with putty or wood filler.
Finishing nails have rounded heads that
can be driven flush with the surface of the wood (Fig. 3). Although they are often
countersunk like casing nails, they can be used without countersinking.
Common brads are designated by length
only (Fig. 4).
Brads are recommended
for light assembly work where the head should be concealed. They are thinner,
shorter, and smaller than finish nails.
Use
the nail selection chart for selecting the proper nail or brad for various thicknesses
of wood (Fig. 5). The chart shows the recommended type and size of nail or brad
for woods of various thicknesses.
FIG.
5
Nail
Selection Chart
Plywood
Thickness
Type
of Nail
Size
3/4"
casing
6d
finishing
6d
5/8"
finishing
6d
- 8d
1/2"
finishing
6d
- 8d
3/8"
finishing
4d
- 6d
1/4"
brads
3/4"
- 1"
finishing
3d
lath
1"
You
may want to make some variations from the chart, but it can be a practical guide
in nail selection.
Here is a
rule of thumb to remember: The nail should always be about three times as long
as the thickness of the wood through which it is driven (Fig. 6). Nails are normally
driven through a thinner piece of wood and into a thicker one. This allows 2/3
of the nail to provide holding power in the thick piece of wood.
To help you pick the right length of nail, hold
the nail up against the thin piece through which it is to be driven. Then select
a nail approximately three times this thickness (Fig. 6).
Fig.
7 illustrates how to countersink a nail. First, select either a casing or finish
nail and drive it into the wood, leaving the nail head slightly above the surface.
Select a nail set with a head the
same size as the head of the nail and drive the head of the nail slightly below
the surface with the nail set.
Remove
the nail set and fill the recessed area with wood putty or wood filler.
Let the putty dry, then sand it flush
with the surface of the wood.
You
can conceal nails in a piece of wood by taking a wood chisel and digging a slight
hole into the wood in the direction of the grain (A, Fig. 8).
Drive a finish or casing nail into the hole and
replace the chipped-out wood with wood cement. If done properly, this will provide
a strong holding power and the nail will be completely hidden (Fig. 8).
Bend nails over at the end when attaching
two pieces of wood where appearance is not important. Bending the nail over increases
the strength of the joint (B, Fig. 8).
Use
care when driving nails near the end of a plank. Never drive two nails in the
same grain of the wood near the end. Always move over to another grain of wood
for inserting the second nail (C, Fig. 8).
When
you must nail an upright piece of wood to a flat surface, toe-nailing with casing
or finish nails will do the job. Drive the nails completely in to provide a strong
holding power with a neat appearance (D, Fig. 8).
A
special type of nail is available for wallboard (Fig. 9). This type of nail practically
eliminates the popping problem.
The
rings around the body of the nail give it an extra-strong holding power. The dish-shaped
head can be driven flush with the surface of the wallboard to provide a neat appearance.
Fig. 10 illustrates various types
of fasteners that are helpful for specific fastening jobs.
A
special nail is available for holding wood to concrete (A). With a little patience
and practice, the concrete nail can be driven into concrete or masonry.
A ring nail provides a strong holding
power for special nailing jobs (B). The annular rings around the nail have sharp
ridges that lock into the wood, making it practically impossible for the nail
to slip.
Ordinary corrugated
fasteners are used for fastening corners or where one piece of wood butts against
another (C).
Upholstery nails
are designed for fastening materials to wood on both flat and curved surfaces
(D). They can be used to cover unsightly tacks.
FIG. 11 - Common types of screws
FIG.
12 - Three common screw heads
FIG.
13 - Two types of screw head slots
FIG.
16 - How to join two pices of wood with screws: (A) Pilot hole; smaller in
diameter than screw body; (B) Screw shank hole; larger in diameter than screw
shank; (C) Countersunk hole; as deep as the screw head or deeper.
FIG.
17 - Use dowel plugs to conceal screw heads. FIG.
18 - Screw washers FIG.
19 - Screw tips
SELECTING THE CORRECT SCREW AND USING IT
PROPERLY
Fig.
11 illustrates the six types of common screws. These screws can be divided into
two basic types: slot-head screws and Phillips-head screws.
Both
types of screws are available with flat, round and oval heads.
Fig. 12 illustrates how these three different
types of common heads look when driven into the wood.
The
oval-head screw extends above the surface in a slight oval. The round-head screw
protrudes above the surface in a half-circle. The flat-head screw is flush with
the surface.
Two basic types
of screwdrivers are needed for driving the different types of screws (Fig. 13).
The regular slotted screw has a slot in the head, while the Phillips-head screw
has a cross slot.
Always use
the proper screwdriver for the screw you are using.
Use
the screw selection chart for selecting the correct size and length of screw for
any job (Fig. 14). This chart is designed for flat-head screws but can be used
for any type.
FIG.
14
Screw
Selection Chart
Plywood
Thickness
Flat-Head
Screws
Screw
Length
Pilot Hole
3/4"
#8
1-1/2"
5/32"
5/8"
#8
1-1/4"
5/32"
1/2"
#6
1-1/4"
1/8"
3/8"
#6
1"
1/8"
1/4"
#4
3/4"
7/64"
The column on the
right shows the size of the pilot hole to be drilled for starting the screw.
The chart in Fig. 15 gives the relative
size of the head and shank of screw sizes ranging from #2 to #16. This will help
you select the proper size screw quickly and easily.
FIG.
15 - Select the right screw for the job.
Fig.
16 shows how to join two pieces of wood with screws. Of course, some of these
steps are not always necessary, but under normal conditions you'll get a neat
bond with excellent holding power.
First,
make a mark where you plan to insert the screws. Carefully position the two pieces
that are to be attached. Securely hold the two pieces together and drill a pilot
hole through the top piece into the second piece (A, Fig. 16). The pilot hole
should be slightly smaller in diameter and as long as the screw. A piece of tape
on the bit will help judge the depth of the hole.
Using
the pilot hole as a guide, drill a hole slightly larger than the screw shank through
the top piece (B, Fig. 16).
Use
a countersink to drill for countersinking oval or flathead screws (C, Fig. 16).
Insert the proper screw. Tighten
the screw for a neat and strong bond of the wood.
You
can make this job easier and the results better if you clamp the two pieces of
wood together while you work. If you do not have clamps, drill, countersink and
tighten one screw first. This will act as a clamp. Then do the remaining screws.
Use a dowel plug if you want to completely
conceal the head of the screw (Fig. 17).
Cut
the holes for the dowel plugs with an ordinary countersink. Simply drill a bit
deeper with the countersink than you would for a regular countersunk screw.
After drilling the hole for the plug,
cut a piece of dowel of the proper size to make the plug.
When
the plug is inserted and glued into place, it can be sanded flush with the wood
or rounded off.
Screw washers
are available for flat-head, round-head or oval-head screws (Fig. 18).
Use ratchet or offset screwdrivers to
insert screws in inaccessible areas. These screwdrivers make it easier to reach
such areas (Fig. 19).
Drill a
hole and insert a dowel to keep the end of a piece of wood from splitting when
screws are inserted. This provides a different run of the grain in the wood and
makes splitting unlikely.
Sometimes
it is necessary to counterbore a thick piece of wood when it is to be attached
to another thick piece of wood.
TOOL AND MATERIAL CHECKLIST
Screws
Slotted Screwdriver
Phillips Screwdriver
Brads
Hand Drill
Wood Chisel
Ratchet Screwdriver
Dowel Plugs
Folding Rule
Nails
Hammer
Countersink
Brad Puncher
Nail Set
Awl
Offset Screwdriver
Screw Washers
Quality Wood Glue
Check
your state and local codes before starting any project. Follow all safety precautions.
Information in this document has been furnished by the National Retail Hardware
Association (NRHA) and associated contributors. Every effort has been made to
ensure accuracy and safety. Neither NRHA, any contributor nor the retailer can
be held responsible for damages or injuries resulting from the use of the information
in this document.
Ask
for Other "Show-How" Instruction Sheets Additional easy-to-use
instruction sheets for home do-it-yourself projects are available from your local
supplier of materials. Come in and ask for "Show-How" instructions when
you get ready for that next handyman project!