Router Bits Guide - Flipbook - Page 42
ROUTER BIT GLOSSARY
N)
O)
P)
R)
Mortise – A hole or recessed area that is made to receive
a corresponding tenon or fixture, whether it be a wood
tenon (see Tenon below) or a hinge plate.
Non-Ferrous metal - Softer metals that contain no
iron. Examples: Aluminum, copper, brass, bronze, titanium, magnesium, zinc, and zirconium.
O-Flute - The gullets of the O flute bit are designed
to "roll" the shavings into a ball for easy removal. The
purpose of this property is to compact the shavings and
make them easier to throw clear of the bit in composite
materials like plastics or non-ferrous metals.
Ogee – An “S”shaped profile involving concave and convex shapes in combination on the edge of the workpiece.
One common version is the Roman Ogee.
Onion Skin - This is a term given by CNC users to describe cutting material in layers (passes). This specifically
references leaving a thin layer of material for the final pass
to ensure all parts don’t move on the table until the bulk
of dimensional cutting is complete.
Oval - A rounded and slightly elongated outline or shape
like that of an egg.
Overall Length (OAL) – The overall length of a router
bit from end to end.
Panel – The center portion (panel) of a cabinet door.
They can be raised-panel or flat-panel. The raised-panel
variety requires the use of router bits or shaper bits to cut
the raised-panel profile. The flat-panel variety is usually
made from a thin piece of plywood or MDF and can vary
in thickness (7/32”, 6mm, or 1/4” most common).
Pattern Bit (top bearing bit) - Similar to a flush trim,
but the bearing is on the top side of the cutting edges
rather than the bottom, like the flush-trim bit.
Plunge – A downward cutting motion of the bit as it
plunges into the thickness of the material to begin its
cut path. It will also plunge deeper into the material as it
changes its “Z axis” (See Axis) during the execution of the
pre-programmed tool path.
Pocket Hole Bit – A pocket hole is a hole drilled at
usually a 15-degree angle for the purpose of joining
two pieces of material together. Some of the machines
involved use an all-in-one bit that pre-drills and countersinks at the same time. Others require a pre-drill bat and
a counter-sink bit separately.
Profile bit - A bit with a shape cut into it, which creates
a specific design or profile.
Rabbet – An “L” shaped notch made along the edge of
a workpiece (not a groove, which is U-shaped), usually
to a specific depth, to allow a mating piece to sit flush
or below the surface. This is seen primarily in cabinetry
where the back meets the sides.
Radius – While the diameter of a circle runs from one
side to the other and cuts through the center of the circle,
the radius begins at the center of the circle and runs to the
outside edge.
Raised Panel – The panel of a cabinet door that varies in
thickness, creating a raised area toward the center, giving
the door a richer, more stylish look. Raised panel bits mill
the edges of the thicker panes down in thickness so that
they can be inserted into the grooves in the stiles and rails.
Roughing Spiral – A roughing spiral, also known as a
ROUTER BITS
hogger, is used for removing a lot of material in the shortest amount of time. This is a process known as hogging
out material. NOTE: This bit is strictly for material removal
and will not leave a clean cut at the top edge of the workpiece.
Round nose (core box) – End cutting bits that plunge
and produce decorative, fluted (U-shaped) grooves.
Round Nose (with bearing guide) - The addition of a
shank-mounted bearing adapts this version of Klingspor’s
round-nose router bit to follow a template.
Round Over or Round Over – A bit used to round over
(or simply “round”) the edge of the workpiece. The bit's
radius can be as small as 1/16” or as large as 2”.
Router bits – The cutting tool, either solid carbide or
carbide tipped, that mounts into a router or CNC to create
grooves, profiles, etc.
S) Shaker Stile & Rail set – The Shaker style of the stile
and rail sets (see Stile & Rail for definition) leaves a square
edge at the inside of the door frame where it meets the
panel, rather than a coved, beaded, or ogee edge of
modern-day door construction. This “square” edge can be
either square (90 degrees) or slightly angled.
Shank – The portion of the router bit that is inserted into
the collet. This part of the bit will have no cutting edges.
Shank diameter(SH) – The measurement of the cylindrical part of the bit that is mounted into the collet. Some
of the most standard shank diameters are 1/4”, 3/8”, and
1/2”, although 5/16”, 5/8”, and 3/4” shank bits can be
found in the market as well.
Shear Angle – The angle at which the cutter “shears” or
slices through the wood.
Slot Cutter – This is similar to a rabbet, but instead
of just an “L” shaped notch, a slot cutter can make a “U”
shaped groove as well. A slot cutter can cut rabbets, but
a rabbet bit cannot cut slots. A slot cutter can be adjusted
to make a tongue and groove as well (see tongue and
groove).
Slow Spiral - A spiral configuration that has a less aggressive twist than standard spiral bits.
Solid Carbide - A router bit that is milled from a solid
carbide blank.
Solid Surface - The material known as solid surface is an
acrylic-based material that contains mineral dust, resins,
and pigments. It is poured and formed into countertops
for kitchens, bathrooms, and other applications. Although
in many cases it looks like stone, this material is relatively
soft and can be cut and formed using router bits and
abrasives.
Speed or Spindle Speed – The speed in revolutions
per minute (RPM) at which the spindle of the CNC router
turns while cutting.
Spiral bit – Straight-sided bits with milled helical
(angled) flutes that spiral around the circumference of the
bit. This provides more efficient chip ejection. These are
typically made of solid carbide and produce a smoother
surface finish. With a spiral, part of the cutter is in the material at all times, compared to a carbide-tipped bit where
the cutting edge touches the material twice per rotation.
Spoilboard – Spoilboards are used as a base surface for
cutting to prevent your CNC table from being damaged by
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the cutting tool. Because of this, a spoilboard needs to be
solid enough that it doesn't compress when the vacuum
pump is turned on while also being porous enough to
allow for appropriate airflow. Spoilboard resurfacing involves a large-diameter router bit flattening the surface
for further use of the board.
Staggertooth Bit - A bit that has two cutting edges
that are staggered along the length of the cutting portion
of the bit. One begins at the tip of the cutting portion of
the bit, and the other begins where the first one ends.
Straight bit – A straight cutting bit with no profiled
shape, either carbide tipped or spiral.
Stile & Rail – A stile and rail set is a set of router bits
that cut the tongue and groove joinery used to construct
cabinet doors, some drawer fronts, and end panels. Part
of the set also cuts the groove that accepts the panel. The
stile is the vertical portion of the door frame and the rail
is the horizontal portion. To easily remember this, think of
the rails of the door frame as the rails of train tracks..laid
horizontally.
T) Template bit – A template bit is similar to a flush-trim
bit. But where a flush-trim bit has the bearing mounted at
the bottom of the cutting edge of the bit, the template bit
has the bearing mounted at the top of the cutting edge.
With the flush-trim, the cutting is done ABOVE the bearing, whereas the template bit does the cutting BELOW the
bearing.
Tenon – A projecting piece of wood made for insertion
into a mortise in another piece.
Tongue & Groove – This is one of the oldest types
of joinery in woodworking. Usually a two-bit set, this
makes a groove on one piece and a tenon (tongue) on the
other. When they are assembled and glued, it makes for
a strong joint. This is typical in wood flooring and similar
applications.
Top Bearing – With the shank end pointing upward,
the bearing will be located at the top of the flutes, or cutting edges.
U) Up-Cut (up shear) – The bit has an upward cutting action, pulling the chips “up” and toward the router motor,
leaving a clean cut on the bottom edge of the workpiece.
This is preferred when making grooves to aid in chip removal. The up-cut action allows for faster cutting as the
chips are cleared from the cut path more efficiently. If a
clean-cut edge is desired on the top edge of the workpiece, this is NOT the configuration to use.
V) V-Groove or V-Bit – A “V” shaped bit used mostly for
carving, lettering, or miter-folding. These bits come with
differing angles measured in degrees.
Z) ZirKon coating – A nano-ceramic coating that, when
added to the carbide, increases the hardness of the cutting edge, and increases the bit’s lubricity, causing it to
run cooler and with less friction. This increases the life of
the bit to 2-3 times the life of an uncoated bit. The Zirkon
coating is a light yellow/gold color. When using o-flute
bits, the Zirkon coating is more suited to non-ferrous metals and composites but will cut plastics and composites,
as well.
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