Glossary of Terms

Quick Jump to Specific Broach Terms:

• Alternate Round and Spline Teeth
• Back Taper
• Back–Off
• Body Diameter
• Broach
• Burnishing Broach
• Burnishing Button
• Chip Breaker
• Chip Gullet
• Chip Per Tooth
• Chip Space
• Chip Breaker Flats
• Combination Broach
• Double Jump Broach
• Dwell Teeth
• External Broach
• Face Angle
• Finishing Broach
• Finishing Teeth
• Follower Diameter
• Front Pilot
• Gullet Radius
• Helical Spline Broach
• Hexagonal Broach
• Holders–Broach Holder
• Holders–Main Holder
• Hook
• Increased Land
• Internal Broach
• Keyway Broach
• Land
• Land, Straight
• Load Gall
• Machines–Continuous Broaching Machine
• Machines–Horizontal Broaching Machine
• Machines–Rotary Broaching Machine
• Machines–Turret Broaching Machine
• Machines–Vertical Broaching Machine

• Pitch
• Progressive Surface Broach
• Pull Broach
• Pull End
• Pull Shank Length
• Puller, Automatic
• Puller, Hairpin Type
• Puller, Key Type
• Puller, Notch Type
• Push Broach
• Rake Angle
• Rear Pilot
• Retriever
• Rifling Broach
• Root Diameter
• Rotor–Kut Broach
• Roughing Broach
• Roughing Teeth
• Round Broach
• Semi–Finishing Teeth
• Shank Length
• Shear Angle
• Shear Cutting Tooth
• Slab Broach
• Spiral Broach
• Spline Broach
• Square Broach
• Steady Rest Spots
• Step Per Tooth
• Straight Land
• Streak
• Strip Broach
• Tearing
• Tooth Form
• Tooth Radius

A type of spline broach which assures concentricity of inside, outside and pitch diameters by alternating spline and round teeth in the finishing section, also called Dwell Teeth

Practice of grinding the form on a broach with a taper from front to back with the back end being lower. This provides relief on the flanks of the cutting teeth. In most cases the form must be calculated to compensate for back taper, also called Back Clearance or Form Relief

Back–Off

An angle on top of the tooth to reduce the amount of broach surface in contact with the part, also called Tooth Relief and Tooth Clearance

The root diameter of a spline on an internal spline broach. It is always smaller than the minor diameter of the part to provide clearance.

Broach

A multiple tooth linear travel cutting tool of bar or slab shape where each tooth takes out a predetermined amount of material.

The root diameter of a spline on an internal spline broach. It is always smaller than the minor diameter of the part to provide clearance.

Burnishing Button

The “teeth” on a Burnishing Broach. Broach tooth without edge. A series of them are sometimes placed after the cutting teeth of a broach to produce a smooth surface.

Notches in the teeth of broaches which break the chips, facilitating their removal. On round broaches they prevent the formation of a solid ring in the chip gullet, also called Chip Grooves, Notches, Nicks

Chip Gullet

See Chip Space

Chip Per Tooth

Depth of cut which determines chip thickness

Space between broach teeth which carries chips during cut, also Chip Gullet

Chip Breaker Flats

Flat areas ground on teeth of round broach to act as chip breakers. Used near finish teeth to avoid streaking

Combination Broach

An internal broach which cuts two or more surfaces at one pass, such as a round and spline broach.

Double Jump Broach

Tool where the cutting teeth are stepped in pairs, usually at higher than normal increments. The first tooth takes out approximately half the width or circumference. The second half takes out the remainder. Commonly used when broaching cast surfaces where the goal is to get under the scale by using heavy cuts.

Dwell Teeth

see Alternate Round and Spline Teeth

A broach which cuts on the external surface of the work piece

Face Angle

Angle of the cutting edge of a broach tooth, also called Hook Angle or Rake Angle.

Finishing Broach

A broach which takes a light finishing cut.

Finishing Teeth

Teeth at the end of broach arranged to take a light cut to finish the surface.

Follower Diameter

That part of the broach which rests in the follower support bushing and may be used as a retriever on the return stroke.

Section of broach used to guide part to first tooth.

Gullet Radius

Curve of space between teeth. These are really two radii, the “face angle radius” just below the cutting edge, and the radius of the back of the preceding tooth called the “heel” radius

Helical Spline Broach

Broach which cuts a helical spline.

Hexagonal Broach

Broach which cuts a hexagon shape hole.

Holders–Broach Holder

That element affixed to the main holder which carries the broaches.

Holders–Main Holder

That element affixed directly to the ram which carries the broach holder

Hook

Part of the tooth form. Varies with types of material being broached and, in some cases, is negative, also called Rake and Face Angle.

Increased Land

A progressive and incremental increase in the amount of a tooth land that is not backed off. This technique allows a tooth to be sharpened more without a subsequent loss of tooth height.

Broach which is pulled or pushed through a hole in the work part to bring the hole to desired size and shape.

Keyway Broach

Broach that cuts a keyway in the bore of a wheel, gear, etc.

Land

Width on the top of the tooth.

A land having no back–off angle, used for finishing teeth to retain broach size after a series of sharpenings.

Load Gall

A buildup of the material being cut on the broach. Usually caused by a dull broach, excessive land, insufficient clearance on the form, or weak (deficient) coolant.

Machines–Continuous Broaching Machine

A high production machine in which the parts are carried through the machine on fixtures mounted on a chain conveyor moving past a series of stationary broaches. Alternately, parts remain stationary and broaches are moved across them. Parts are loaded by the operator at one end of the machine and drop out of the fixtures at the other end.

Machines–Horizontal Broaching Machine

Broaching machine that moves the broach in a horizontal plane.

Machines–Rotary Broaching Machine

A high production broaching machine in which broaches are mounted in broach holding columns at the periphery of the machine. The parts to be broached, clamped in fixtures, are carried on a rotary table past the broaches.

Machines–Turret Broaching Machine

Multiple broaching machine with turret action.

Machines–Vertical Broaching Machine

Broaching machine in which broaches move vertically, either up or down.

Pitch

Measurement from the cutting edge of one tooth to the corresponding point on the next tooth, also called Tooth Spacing and Tooth Index.

Progressive Surface Broach

Surface broach equipped with one or more sets of teeth narrower than the width of the surface to be broached. These are fanned out at an angle so that the entire width of the work piece is machined only by a complete pass of the broach.

Broach that is pulled through or over the surface of the work piece.

Pull End

That end of a broach at which the broach is coupled to the puller of the broaching machine.

Pull Shank Length

The distance from the puller end of the broach to the first tooth.

A device used for pulling a broach that automatically locks onto the pull end of the broach to pull the broach, also called Sleeve Type Puller.

A manually operated device used for pulling a broach. Used on small diameter pull shanks, also called Pin Type Puller, Notched Type Puller.

A mechanically operated device used for pulling a broach. Usually used for low production jobs, also called Slot Type Puller.

Device used for pulling a broach on keyways and other flat internal surfaces.

Broach that is pushed through or over the surface of the work part.

Rake Angle

See Hook.

Section of broach at rear to guide the part past the last tooth.

An automatically operated device used to return a broach to starting position. Sometimes an automatic or notch type puller is used.

Rifling Broach

Broach for rifling gun barrels. Spiral type broach, usually with long pitch, to provide large chip space.

The diameter at the bottom of the tooth gullet depth on a round or cylindrical broach.

Broach with cutting teeth designed so parallel segments of an internal surface are progressively cut from solid stock. Portions of the stock remain at each side of each cutting tooth. Final teeth are round.

Roughing Broach

A broach which is designed for the roughing operation. Must be followed by a finishing broach.

Roughing Teeth

The teeth which take the first cuts in any broaching operation. Generally they take heavier cuts than succeeding teeth.

Round Broach

Broach of circular section.

Semi–Finishing Teeth

Broach teeth, just ahead of the finishing teeth, which take the semi–finishing cut.

Portion of broach in front of teeth. Includes pull end and front pilot.

Shear Angle

The angle between the cutting edge of a shear tooth and a line perpendicular to broach axis or line of travel

Tooth positioned so it does not run perpendicular to the direction of broach motion. Most often on surface or external broaches. Cuts with a shear action with maximum tooth overlap.

Slab Broach

Flat, slab shape surface broach.

Spiral Broach

Broach with a continuous spiral shaped tooth gullet. Vibration is reduced because the cutting teeth are always engaged.

Spline Broach

Internal broach for cutting splines.

Square Broach

An internal broach for cutting a square hole.

Cylindrical ground sections between teeth. Used to provide steady rests while grinding and sharpening.

Progressive increase in tooth size from tooth to tooth of a broach. Usually greater in roughing teeth than in semi–finishing teeth. Action of step height produces the equivalent of feed in other types of machining.

Straight Land

The portion at the top of a broach tooth that is relieved or backed off.

Streak

A mark on the finish of a part usually caused by chip breakers or moving of the part while broaching, see also Tearing.

Strip Broach

A broach that is pushed through the part and then pulled or stripped back through in the opposite direction. Greatly reduces cycle times because the tool never needs to be hooked and unhooked from a puller. Applicable only where the length of the cutting section of the tool is relatively short in comparison to its diameter or cross–sectional area.

Tearing

A gouge or rip in the surface of the part usually caused by a dull broach, loading, insufficient chip room, insufficient clearance, weak (deficient) coolant, hydraulic oil in coolant, or insufficient heat, see also Streak.

The shape of the cutting section of a broach, also called Tooth Shape and Tooth Profile.

Tooth Radius

The radius at the tooth depth used to curl the chips, also called Root Radius and Gullet.