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QUICK FACT GUIDES FOR MACHINISTS
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GUIDES
FUNDAMENTALS OF
DRILLING & TAPPING
FUNDAMENTALS
OF THE LATHE
FUNDAMENTALS
OF MILLING
FUNDAMENTALS
OF SAWING
METALWORKING
SHOP TERMS |
REAMER TERMS ACTUAL
SIZE: The
actual measured diameter of a reamer, usually slightly larger than the nominal
size to allow for wear. ALTERNATE:
Reamer
features which differ from each other in turn in a regular sequence such as
cutting edges, chip breakers, chamfers, or flutes. ANGLE
OF TAPER:
The included angle of taper on a taper tool or taper shank. ANGULAR
FLUTE:
See Flutes. ARBOR
HOLE: The
central mounting hole in a Shell Reamer. AXIS:
The imaginary straight line which forms the longitudinal centerline of a reamer,
usually established by rotating the reamer between centers. BACK
OFF:
See preferred term Relief. BACK
TAPER: A
slight decrease in diameter, from front to back in the flute length of reamers BARREL:
See
preferred term Body. BELL
MOUTH HOLE: A
hole which is larger in diameter at the start of the hole than as some distance
beyond. BEVEL:
An
unrelieved angular surface of revolution. (Not to be confused with chamfer). BLADE:
A
tooth or cutting element inserted in a reamer body. It may be adjustable and\or
replaceable. BLENDING
RADIUS: A
relieved radius joining the chamfer and the periphery. BODY:
(1) The fluted full diameter portion of a reamer, inclusive of the chamfer,
starting taper and bevel. (2) The principal supporting member for a set of
reamer blades, usually including the shank. BURNISHING
REAMER:
A finishing reamer intended to take a light scraping cut and impart a fine
finish. CHAMBERING
REAMER:
A reamer (usually one of a series) for forming a shell chamber, etc. CHAMFER:
The
angular cutting portion at the entering end of a reamer. See also Secondary
Chamfer. CHAMFER
ANGLE:
The angle between the axis and the cutting edge of the chamfer measured in an
axial plane at the cutting edge. CHAMFER
RELIEF ANGLE: See
Relief. CHAMFER
RELIEF: See
Relief. CHIP
BREAKERS:
Notches or grooves in the cutting edges of some taper reamers designed to break
the continuity of the chips. CHUCKING
REAMERS:
A type of machine reamer with relatively short straight or helical flutes on
which the peripheral lands are relieved. They have a relatively small amount of
back taper and have either straight or taper shanks. CIRCULAR
LAND: See
preferred term Margin. CLEARANCE:
The space created by the relief behind the cutting edge or margin of a reamer. CORE:
The
central portion of a reamer below the flutes which joins the lands. CORE
DIAMETER: The
diameter at a given point along the axis of the largest circle which does not
project into the flutes. CORE
REAMER:
A roughing reamer with deep wide flutes to provide ample room for chips in
reaming cored holes. CUTTER
SWEEP: The
section removed by the milling cutter or grinding wheel in entering and leaving
a flute. CUTTING
EDGE: The leading edge of
the land in the direction of rotation for cutting. CUTTING
FACE: The
leading side of the land in the direction of rotation for cutting on which the
chip impinges. CUTTING
SPEED:
The peripheral lineal speed resulting from rotation, usually expressed as
surface feet per minute. (sfm). DRIFT:
A
flat tapered bar for forcing a taper shank out of its socket. DRIFT
SLOT:
A slot through a socket at the small end of the tapered hole to receive a drift
for forcing a taper shank out of its socket. DUPLEX
LEAD REAMER:
A reamer with one or more flutes having a different lead than the other flutes.
This produces a continuous change in flute spacing. END
CUTTING: A
general term describing the extent to which a reamer cuts on the end. Four types
are recognized.
(1) End Cutting on the chamfers only. (2) 10 degree End Cutting to the bottom of
the flutes (Core Diameter). (3) 180 degree End Cutting to the center of hole or
specified diameter of a circle. (4) 180 degree End Cutting to the center of the
reamer. EXTERNAL
CENTER: The
pointed end of a reamer. The included angle varies with manufacturing practice. FLUTES:
Longitudinal channels formed in the body of the reamer to provide cutting edges,
permit passage of chips and allow cutting fluid to reach the cutting edges.
ANGULAR
FLUTE: A
flute which forms a cutting face lying in a plane intersecting the reamer axis
at an angle. It is unlike a helical flute in that it forms cutting face which
lies in a single plane.
HELICAL
FLUTE:
(Sometimes called a "spiral flute") A flute which is formed in a
helical path around the axis of a reamer.
SPIRAL
FLUTE: (1)
On a tape reamer a flute of constant lead. (2) In reference to a straight
reamer, see preferred term Helical Flute.
STRAIGHT
FLUTE: A
flute which form a cutting edge lying in an axial plane. FLUTED
CHUCKING REAMER: See
preferred term Chucking Reamer. FLUTE
LENGTH:
The length of the flutes not including the cutter sweep. GAGE
LINE: The
axial position on a taper where the diameter is equal to the basic large end
diameter of the specific taper. GRINDING
RECESS:
A clearance for the edge or corner of a grinding wheel, usually necessary at a
change of diameter. GUIDE:
A cylindrical portion following the flutes of a reamer to maintain alignment. HALF-ROUND
REAMER:
A reamer with a transverse cross-section of approximately half a circle and
having one cutting edge. HEEL:
The trailing edge of the land in the direction of rotation for cutting. HELIX
ANGLE:
The angle which a helical cutting edge at a given point makes with an axial
plane through the same point. HOOK:
See definition under Rake. INTERNAL
CENTER:
A 60 degree countersink with clearance at the bottom, in one or both ends of a
tool, which establishes the tool axis. IRREGULAR
SPACING: A
deliberate variation from uniform spacing of the reamer cutting edges. LAND:
The
section of the reamer between adjacent flutes. LAND
WIDTH: The
distance between the leading edge of the land and the heel measured at a right
angle to the leading edge. LEAD:
See
preferred term Starting Taper. LEAD
OF FLUTE:
The axial advance of a helical or spiral cutting edge in one turn around the
reamer axis. LENGTH:
The
dimension of any reamer element measured parallel to the reamer axis. LINE
REAMER:
A reamer used to ream two or more separate holes on the same axis. MARGIN:
The unrelieved part of the periphery of the land adjacent to the cutting edge. MULTIPLE
DIAMETER REAMER:
A reamer with two or more cutting diameters. NECK
A section of reduced diameter connecting shank to body, or connecting other
portions of the reamer. NOTCHES:
See preferred term Chip Breaker. OIL
GROOVES: Longitudinal
straight or helical grooves in the shank, guide, or pilot for lubrication or to
carry cutting fluid to the cutting edge. OIL
HOLES:
Holes through which a cutting fluid is fed to the cutting edges of a reamer. OVERALL
LENGTH:
The extreme length of the complete reamer from end to end, but not including
eternal centers or expansion screws. PERIPHERY:
The
outside circumference of a reamer. PILOT:
A
cylindrical portion preceding the entering end of the reamer body to maintain
alignment. PULL
REAMER: Reamers
which are designed to be pulled through long holes (such as gun barrels) while
reamer or workpiece is rotated. RADIAL
RAKE ANGLE: See
definition under Rake. RADIAL
RUNOUT: The
radial variation from a true circle which lies in the diametral plane and is
concentric with the reamer axis. RAKE:
The angular relationship between the cutting face, or a tangent to the cutting
face at a given point and a given reference plane or line.
AXIAL
RAKE: Applies
to angular (not helical or spiral) cutting faces. It is the angle between a
plane containing the cutting face, or tangent to the cutting face at a given
point, and the reamer axis.
HELICAL
RAKE:
Applies to helical and spiral cutting faces only, (not angular). It is the angle
between a plane tangent to the cutting face at a given point on the cutting
edge, and the reamer axis.
HOOK:
A concave condition of a cutting face. The rake of a hooked cutting face must be
determined at a given point.
NEGATIVE
RAKE: Describes
a cutting face in rotation whose cutting edge lags the surface of the cutting
face.
POSITIVE
RAKE: Describes
a cutting face in rotation whose cutting edge leads the surface of the cutting
face.
RADIAL
RAKE ANGLE: The
angle in a transverse plane between a straight cutting face and a radial line
passing through the cutting edge.
TANGENTIAL
RAKE ANGLE: The
angle in a transverse plane between a line tangent to a hooked cutting face at
the peripheral cutting edge and a radial line passing through this point of
tangency. RECESS:
See preferred term Grinding Recess. RELIEF:
The
result of the removal of tool material behind or adjacent to the cutting edge to
provide clearance and prevent rubbing. (heel drag).
AXIAL
RELIEF: The
relief measured in the axial direction between a plane perpendicular to the axis
and re the relieved surface. It can be measured by the amount of indicator drop
at a given radius in a given amount of angular rotation.
CAM
RELIEF:
The relief from the cutting edge to the heel of the land produced by a cam
action.
CHAMFER
RELIEF: The
axial relief on the chamfer of the reamer.
CHAMFER
RELIEF ANGLE:
The axial relief angle at the outer corner of the chamfer. It is measured by
projection into a plane tangent to the periphery at the outer corner of the
chamfer.
ECCENTRIC
RELIEF:
A convex relieved surface behind the cutting edge.
END RELIEF: See
preferred term Axial Relief.
FLAT RELIEF:
A relieved surface behind the cutting edge which is essentially flat.
PRIMARY RELIEF: The
relief immediately behind the
cutting edge or margin. Properly called relief.
RELIEF ANGLE: The
angle, measured in a transverse plane, between the relived surface and a plane
tangent to the periphery at the cutting edge.
RADIAL RELIEF:
Relief in a radial direction measured in the plane of rotation. It can be
measured by the amount of indicator drop at a given radius in a given amount of
angular rotation.
SECONDARY RELIEF:
An additional relief behind the primary relief. RELATIVE
ECCENTRICITY: The
distance between the axis of one portion and the axis of some other portion of a
reamer. ROSE
REAMER: See
Reamer Types. RUNOUT:
See
Radial Runout. SALVAGE
HOLE:
A central hole in the front end of a reamer of sufficient depth to provide for
reconditioning. SECONDARY
CHAMFER: A
slight relieved chamfer adjacent to and following the initial chamfer on a
reamer. SHANK:
The
portion of the reamer by which it is held and driven. SLEEVE:
A
tapered shell designed to fit into a specified socket and to receive a taper
shank smaller than the socket. SOCKET:
The tapered hole in a spindle, adapter or sleeve, designed to receive, hold, and
drive a tapered shank/ SPIRAL
FLUTES:
See Flutes. SQUARED
SHANK: A
cylindrical shank having a driving square on the back end. STAGGERED
FLUTES: See
preferred term Irregular Spacing. STARTING
RADIUS:
A relived radius at the entering end of a reamer in place of a chamfer. STARTING
TAPER: A
slight relived taper on the front end of a reamer. STEP
REAMER: A
multiple diameter reamer with all lands in each step ground to the same
diameter. Used to ream a hole of two or more diameters. STRAIGHT
SHANK:
A cylindrical shank. STRAIGHT
FLUTE:
See Flutes. SUBLAND
REAMER: A
type of multiple diameter reamer which has independent sets of lands in the same
body section for each diameter. TANG:
The flatted end of a taper shank which fits a slot in the socket. TANG
DRIVE:
Two opposite parallel driving flats on the extreme end of a straight shank. TAPER
PER FOOT:
The difference in diameter between two points 12 inches apart measured along the
axis. TAPE
SHANK: A
shank made to fit a specified (conical) taper socket. TAPER
SQUARE SHANK:
A taper shank whose cross-section is a square. TONGUE:
See preferred term Tang. UNDERCUT:
See
preferred term Grinding Recess. WEB:
See
preferred term Core Diameter. |
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Copyright © 2002 QUICK FACT GUIDES FOR MACHINISTS
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