Saws
STANDARD HANDSAWS
Handsaws have 14" to 26" blades.
Fineness of cut depends on the number of cutting teeth per
inch and tooth shape. A coarse crosscut saw with seven or
eight teeth per inch is best for fast, rough work or for use
on green wood. A fine-tooth crosscut saw with 10 or 11 teeth
per inch is best for smooth, accurate cutting on dry, seasoned
wood.
Some handsaws are available with special
"aggressive-design" teeth-three cutting edges instead of the
conventional two. They cut on both the forward and backward
stroke, thereby cutting several times faster than saws with
traditional teeth. They may also have the teeth induction
hardened to help keep them sharp longer.
Quality features in saws include:
- Tempered alloy blades. Lower grade steel quickly loses
sharp edge but is easy to sharpen.
- Rust-resistant or Teflon-S blade finish. Teflon-coated
handsaws reduce many binding and residue buildup problems
inherent to wood cutting. Reduced friction or drag makes for
smoother, easier cutting.
- Hardwood or sturdy plastic handle.
- Special aluminum or plated-steel nuts and bolts to
fasten blade to handle.
- Taper-ground blades, thicker at the cutting edge, to
prevent binding in the cut.
- Bevel-filed teeth evenly set in two alternate rows, one
row to the right of center, one row to the left; produces a
groove or kerf slightly wider than the thickest part of the
blade; prevents or reduces binding while sawing.
RIPSAWS
A ripsaw has large, chisel shaped
teeth, usually -1/2 teeth per inch, and is made to cut with
the wood grain. Blade lengths measure from 24" to 28". Teeth
are cross-filed to assure that the chisel point is set square
to the direction of cutting for best performance. This saw is
best held at a 60° angle to the surface of the board being
cut. The ripping action of the saw produces a coarse, ragged
cut which makes the saw unsatisfactory for finish work.
BOW SAWS
Bow saws Bow saws consist of a
tubular steel frame and a saw blade for fast cutting of all
woods.
The bow saw's frame is important, since the thin blade,
usually 3/4" wide, must be held under high tension for fast
cutting.
Advantages of this general-purpose saw are its all-round
utility and light weight.
Quality features include a tension-lever clamp for fast
blade insertion and replacement, and hardened, tempered steel
blades for longer life.
In 21", 24" and 30" lengths, bow saws normally have teeth
placed in groups. Within each group, distance between teeth
varies, insuring a smooth, vibrationless cut. Wide gullies
provide ample space for sawdust to accumulate without binding
the saw.
In the 36", 42" and 48" lengths, the most popular toothing
pattern provides for two cutter teeth to each raker tooth.
This combination of teeth ensures maximum cutting ability in
these longer lengths, regardless of wood hardness.
"Hard-point" blades, with tips as hard as an ordinary file,
eliminate resharpening. Base of teeth and body of blade have
normal hardness. Because blade stays sharp, cutting is faster
and easier.
COMPASS OR KEYHOLE SAWS
Keyhole or compass saws cut curved or
straight-sided holes. Saw blades are narrow, tapered nearly to
a point to fit into most spaces. Blades come in three or four
styles that can be changed to fit the job.
Turret-head keyhole blades can be rotated and locked in
several positions for easier cutting in tight, awkward
spots.
HACKSAWS
Hacksaws are fine-toothed saws
designed to cut metal. The saws consist of a blade held in a
steel frame with relatively high tension.
High-tension models (with tension to 32,000 p.s.i.) are
also available. High tension holds the blade more rigidly
straight, which enables the user to make fast, straight cuts.
Blade life is also increased. Look for a quick-release blade
change mechanism, tension guide and rugged frame on these
models.
Blades come in several designs; among them are coarse,
medium, fine and very fine-toothed.
Regular or standard blades are used for general-purpose
cutting; high-speed or bi-metal blades are for cutting hard,
extra-tough steel.
The medium blade has 18 teeth per inch and is good for
cutting tool steel, iron pipe and light angle iron.
A fine blade, which has 24 teeth per inch, cuts drill rod,
thin tubing and medium-weight materials.
The very fine blade, with 32 teeth per inch, is used for
extra thin materials, light angle irons, channels, wire rope
and cable.
As a guide to selecting the right blade, find out what
material will be cut; then suggest a blade that will have at
least three teeth in contact with the material.
Frames vary in style and price. Most can be adjusted to
hold various blade lengths. Some have both horizontal and
vertical positions for blades. Others provide blade
storage.
A close-quarter hacksaw holds and positions a hacksaw blade
so it can be used effectively in narrow spaces and slots.
Quality models of these saws may also have
induction-hardened teeth for longer life without
sharpening.
DOVETAIL SAWS
A dovetail saw blade is constructed
with the same reinforced ridge found on a backsaw, giving it
added rigidity and greater precision.
This saw cuts a true, smooth, narrow kerf. It has a
straight handle for precise, positive grip. Teeth are very
fine for smooth work. Dovetails are used in picture framing,
cabinet work, toy making, etc.
COPING SAWS
Coping saws cut irregular shapes and
intricate patterns. They consist of a saw blade and steel
tension frame. The blade is removable. Blade sizes range from
the rotary or wire type to 1/8" wide.
Interior cuts, such as an entry hole for a birdhouse, are
made by first drilling a hole, then threading the blade
through it and attaching it to the frame. On the frame are
clamps, called pawls, with slots into which the blade fits.
Some blades are made to turn on the frame; other blades,
called spirals, have the advantage of being able to cut in any
direction without turning the saw.
WALLBOARD SAWS
This saw resembles a kitchen knife in design. It will cut
plasterboard in the same fashion as a keyhole saw and is used
for sawing holes for electric outlets, switchplates, etc. The
saw is self-starting with a sharp point for plunge cuts.
Wallboard or drywall saws may also
have induction teeth for longer life without sharpening.
VENEER SAWS
Veneer saws are specially designed
for sawing thin materials such as wood paneling. The blade is
curved downward at the end, with cutting teeth on the curved
part of the back to saw slots or grooves in the panel with
minimum damage. Standard saw lengths are about 12"-13", with
14 teeth per inch.
ROD SAWS
Rod saws are a form of hacksaw-type
blades, used in regular hacksaw frames and capable of cutting
through most hard materials-spring and stainless steel, chain,
brick, glass and tile.
The blade consists of a permanently bonded tungsten carbide
surface on a steel rod. Because the blade is round, it can cut
in any direction.
CROSSCUT SAWS
Most commonly used crosscut saws are
10 to 12 point for fine work and 7 or 8 point for faster
cutting. Ten teeth per inch is considered general purpose,
12-point being used for cabinet work. Teeth are shaped like
knife points to crumble out wood between cuts. Best cutting
angle for this saw is about 45°. Blade lengths range from 20"
to 28", 26" is most popular.
LOGGING CROSSCUT
A large, two-man logging saw another
form of crosscut saw-a long steel blade with wooden handles on
both ends. Cutting is done as the loggers pull the saw back
and forth between them across a tree or log.
BACKSAWS
A backsaw is a thick-bladed saw with
reinforced back to provide the rigidity necessary in precision
cutting. It varies in length from 10" to 30" and is found in
tooth counts from seven to 14 teeth per inch.
MITER BOXES
Miter boxes are used to help cut
exact angles for wood trim, rafters, etc. Better models
provide a mechanism for a backsaw.
Quality boxes provide more accuracy for deep cuts and have
exact adjustments and calibrations. They have length gauges to
aid in duplicating pieces and stock guides to allow for proper
cuts on intricate molding. Other marks of quality are roller
bearings in the saw guide and grips that hold the saw above
work so both hands can be used to position the piece.
Some boxes feature magnetic mount guides. The magnets grasp
and hold the saw to the miter box saw guide or hold the saw
blade to the plane of the saw guide. This helps assure an
accurate miter cut without impairing the saw stroke.
SAW SETS
Most saws become dull with use and need periodic filing and
resetting. A saw set is used to reset or bend teeth back to
their original position so teeth will make a cut wider than
the blade to avoid binding in the cut or kerf.
Most sets are made with a pistol grip and designed so the
saw teeth are visible during setting. A good saw set should
have enough calibrations to ensure an even set to each tooth.
Saw sets can be used on back-, hand- and small circular saws
with 4 to 16 points.
UTILITY KNIVES
Utility knives are designed to cut
heavy materials such as carpet, flooring, roofing, cardboard
cartons, laminates and plastic. Blades can be replaced by
disassembling the handle or ejecting them by depressing a
spring-release button on the handle. Some knives swivel open
to permit blade replacement.
Aluminum-bodied knives have superior strength and
durability for heavy use. Locking features that hold blades
securely between knife halves are available.
Extra blades can be stored in the handle. In many models,
the blade is retractable so the knife can be carried in a
pocket. Some models have "breakaway" points that keep scoring
and cutting edge sharp. Miniature, pocket and hobby knives are
available in various styles and sizes for whittling, modeling
and trimming.
CIRCLE CUTTERS
Circle cutters cut circular holes in
sheets of metal, wood, plastic, hardboard, brass, copper, mild
steel, aluminum or composition materials.
The cutter features a regular center drill with a cutting
tool mounted on an adjustable bar. Diameter of the circle is
regulated by a setscrew adjustment on the cutting bar.
Downward pressure is applied as the regular bit pulls into the
material and forces the cutting tool down in a slowly lowering
circle.
Ground, hardened cutting tools assure clean, even cutting
in a variety of materials. Cutting edges available on hole
cutters include high-speed steel bi-metal, carbide grit and
diamond grit. Each cutting edge is designed to work best on
specific materials. Bi-metal for metal, wood, plastic, etc.;
carbide for tile, brick, fiberglass and hard composites;
diamond for glass, ceramics and other abrasive materials.
Due to the unbalanced load inherent in the design of these
tools, for safety's sake, they must be used only in drill
presses or drill stands and never with a handheld drill.
Keep Cutting Tools Sharp
| Six basic rules apply to redressing chisels
and other tools with a cutting edge: |
| 1. Always wear safety goggles. |
| 2. Tool must be returned to its original
shape. |
| 3. Discard any tool with cracks or
chipping. |
| 4. Temperature must be kept low. |
| 5. A medium or fine whetstone file should be
used. |
| 6. Wheel direction should always be from the
cutting edge toward the body of the tool. This directs
heat away from the cutting edge. |
| Cold chisels are generally hardened about
1-1/2' back from the cutting edge and about 3/4" back
from the head. Redressing should be kept within these
limits. The correct cutting edge bevel may vary from 55°
through 90°. for all around use, 70 degrees is a good
compromised. Soft metal bevel may be as low as 55
degrees and hard steel bevel as high as 90
degrees. |
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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. |