Ruch Carbide Burs, Inc.

Apex - The tip or angular summit of the tool,
opposite the shank end.

Axis - The center line extending thru the shank
and head on which the tool rotates.

Blank - The material of the tool in a finished
or semi-finished state before the teeth have
been ground.

Braze - The method employed to join two
metals by a film silver solder or copper fused
at high heat.

Bur - A rotary cutting tool having teeth ground
onthe circumference and manufactured in
various shapes and sizes. Also called a rotary
file.

Carbide - A man-made metal of extreme
hardness, consisting primarily of carburized
tungsten with a colbalt binder sintered at high
heat.

Center Fluting - A fluting arrangement having
all of the teeth equally spaced and converging
at a common point at the apex of the tool.

Chip Breaker - Serrations in the cutting edge
of the tooth which prevent formation of long
chips.

Cut - Designation used to indicate the rotation
of the tool, as right hand cut or left hand cut.
Also used to describe the tooth spacing, as
fine, standard, or coarse cut.

Diamond Cut - An additional fluting of
opposite hand or spiral with approximately
10% fewer teeth, resulting in a tooth shape or
pyramid form.

End Cut - Fluting as applied to the plane
perpendicular to the axis at the cutting end of
the tool.

FIllet or Gullet - The curved part at the
bottom of the flute (formed by the intersection
of the tooth face and the back of the next
tooth.

Flute - The space between the cutting teeth.

Hand Ground - The method of producing
cutting teeth on accurately formed blanks by
off-hand grinding.

Head - The portion of the tool having the
cutting teeth.

Helix Angle - The angle that the flute makes
with the center line. Can be either R.H. or
L.H., but is usually R.H. unless otherwise
noted.

Land - A Section of the tooth reinforcing the
cutting edge. It may or may not be relieved.

Major Diameter - The largest diameter of the
tool.

Machine Ground - The method of forming
cutting teeth by automated machine grinding

Negative Rake - The angle by which the face
of the tooth is displaced ahead of the radial
line.

Positive Rake - The angle by which the face of
the tooth is displaced behind the radial line.

Radial Rake - The condition in which the face
of the tooth coincides with the radial line and has
no rake angle.

Rake - The angle by which the face of the tooth
is displaced ahead or behind the radial line drawn
from the cutting edge to the center of the
rotation.

Recondition - The term applied when extensive
reworking (including rebrazing, replacing shanks,
and removing badly chipped sections) is
necessary to restore a used tool to working
condition.

Resharpen - The term applied to the work
necessary to restore a normally worn and dull
tool to working condition.

Rotary File - A rotary cutting tool having teeth
ground on the circumference and manufactured
in various shapes and sizes. Also called a bur.

Salvage - When extensive reworking (including
rebrazing, replacing shanks, and removing badly
chipped sections) is necessary to restore a used
tool to reworking condition. This process
involves totally removing all flutes on the tool
and starting with a clean, smooth blank. Then the
total reflute process is done to restore exactly as
a new tool, but smaller in diameter by
approximatley .030 inches.

Sectional Fluting - A fluting arrangement
having a small portion of the teeth evenly spaced
and converging at a common point at the apex of
the tool

Shank - The portion of the tool which is
gripped or chucked by the driver.

Shape - The form or profile of the cutting head.

Shoulder - An enlarged section of the shank
against which the head locates.

Spiral Angle - The angle that the flute makes
with the center line. Can be either R.H. or L.H.,
but is usually R.H. unless otherwise noted.

Supercut - An additional fluting cut of opposite
hand of spiral except with approximately 50%
fewer teeth, resulting in a tooth shape of wedge
or chisel form.

Tooth - Portion of the tool left between the
flutes.

Tooth Clearance - The amount by which the
heel of the land clears the path made by the
cutting edge, measured in degrees or indicator
drop.

Tooth Depth - The distance from the cutting
edge to the bottom of the flute.

Tooth Face - The part of the tooth that faces
the direction or rotation.