Setup for the Cylindrical Grinder 242

abrasive grain

A small, hard particle that forms chips during grinding. Abrasive grains are bonded together to create grinding wheels and other abrasive tools.

adjusting screw

A screw that gradually moves the swiveling upper table on a universal cylindrical grinding machine. The adjusting screw provides precise and easy swiveling.

alloy steel

Steel that contains intentionally added materials that change the property of the metal. Alloy steel can be difficult to grind because of its hardness levels and may require a superabrasive.

aluminum

A lightweight, nonferrous metal. Aluminum workpieces can be ground using a friable abrasive grain.

aluminum oxide

A chemical compound of aluminum and oxygen that is used as a conventional abrasive. Aluminum oxide is resistant to heat and electricity.

American National Standards Institute

ANSI. A private, nonprofit organization that coordinates voluntary standards and systems. The American National Standards Institute sets standards for grinding safety in ANSI B7.1.

angle dressed

A grinding wheel that has been dressed to create a specific angle or profile. An angle-dressed wheel creates specific features on a workpiece.

angular truing attachment

A cylindrical grinder accessory that creates angled features on a grinding wheel. An angular truing attachment uses a diamond dresser to true the wheel.

ANSI B7.1

A document published by the American National Standards Institute (ANSI) describing the necessary standards for grinding safety. ANSI B7.1 is the basis for OSHA standards regarding grinding safety in the workplace.

arcs of contact

The portion of the grinding wheel periphery that is in contact with the workpiece at any point. A smaller arc of contact generally requires a harder grinding wheel.

automatic wheel balancers

An electronic device on a grinding machine that detects and corrects grinding wheel imbalance throughout a grinding operation. Automatic wheel balancers save time and effort by continuously balancing the wheel.

axis

The imaginary line around which a part rotates. The axis of a workpiece in cylindrical grinding passes through the middle of the part.

balancing

The process of positioning weights on a grinding wheel before mounting it on the machine. Balancing a grinding wheel equally distributes weight.

bearings

A friction-reducing device that allows machine parts to move together without excess wear or friction. Bearings in the wheelhead spindle can be damaged by excess vibration.

bond material

The adhesive substance in a grinding wheel that holds the abrasive grains together. Bond materials include vitrified, resinoid, or metal materials.

bore

The interior diameter of a hollow cylindrical workpiece. Bores are finished or enlarged by inside-diameter grinding.

brittle

Difficult to bend, stretch, or form without breaking. Brittle abrasive grains break down more easily to create new cutting edges on the grinding wheel.

CBN

Cubic boron nitride. A synthetic superabrasive with a hardness level that is second only to diamond. CBN can be used to grind ferrous metals.

cemented carbides

A hard material consisting of fine carbide particles combined with a binder metal, such as cobalt. Cemented carbide workpieces can be ground using a superabrasive.

center holes

A hole drilled into the end of a workpiece in order to fit a workholding center. Center holes must be checked for alignment in center-type cylindrical grinding.

center steady rest

An accessory on the cylindrical grinder that provides support for long, slender workpieces. Center steady rests reduce vibration.

center tension

The amount of pressure that the tailstock center applies to the workpiece in center-type grinding. Center tension is adjusted during machine setup.

centers

A hardened, pointed, cylindrical component used to hold one of two workpiece ends during center-type cylindrical grinding. A center's tip is inserted into a matching hole on the end of a workpiece.

center-type grinding

A type of cylindrical grinding that mounts the workpiece between two centers. Center-type grinding may rotate the workpiece using live centers or dead centers combined with other devices.

ceramic aluminum oxide

An exceptionally tough and sharp conventional abrasive that is formed from aluminum oxide. Ceramic aluminum oxide grains are very fine and produce refined surface finishes.

ceramics

A hard, refractory material that has low tensile strength. Ceramic workpieces are best ground using a diamond grinding wheel.

chatter

Unwanted vibration between a workpiece and a grinding wheel. Chatter negatively impacts surface quality and increases tool wear.

chips

An unwanted piece of material that is removed from a workpiece during grinding. Chips form when an abrasive grinding wheel grinds a workpiece.

chucking-type grinding

A form of cylindrical grinding that uses a chuck or collet to hold and locate the workpiece in the headstock. In chucking-type grinding, a chuck or collet rotates the workpiece directly.

chucks

A workholding device that holds a workpiece in the headstock as it rotates. A chuck has moveable jaws that adjust to fit workpiece dimensions.

clamping screw

A screw that fixes one component of a grinder to another. Clamping screws must be loosened to swivel the upper table or headstock on a cylindrical grinder for taper grinding.

clearance

An intentional amount of space left between two components as a safety precaution. Grinding wheel clearance measures the space between the wheel and workpiece.

coarse

Large grains in an abrasive tool. Coarse grains produce the roughest surface finish.

collets

A slitted workholding device that holds a workpiece in the headstock as it rotates. A collet has a hole through which the workpiece passes and is designed to hold a range of workpiece dimensions.

computer numerical control

CNC. The use of computers, programs, and motors to automatically control tool movement and carry out sequences of machining operations. Computer numerical control grinding machines require an operator for setup, but automatic or computerized actions control the machine movement.

concave

Hollowed out or curving inward. Concave features on a grinding wheel can be produced using the radius truing attachment.

concentric

Sharing a common center between two circular or cylindrical features. Concentricity between the center hole on a grinding wheel and its outside edge is a characteristic of a balanced wheel.

conventional abrasives

The category of abrasive materials that includes the most commonly used, inexpensive abrasives. Conventional abrasives can grind a wide range of workpieces.

convex

Curving outward like the exterior of a circle or sphere. Convex features on a grinding wheel can be produced using the radius truing attachment.

coolant

A liquid used during grinding to clean, cool, and lubricate the grinding wheel and workpiece. Coolant, also known as grinding fluid, helps to prevent a loaded or clogged grinding wheel.

crossfeed handwheel

A grinding machine control that moves the wheel into and away from the workpiece. The crossfeed handwheel is used to control the infeed.

cubic boron nitride

CBN. A synthetic superabrasive with a hardness level that is second only to diamond. Cubic boron nitride can be used to grind ferrous metals.

cutoff

A grinding operation that uses a thin grinding wheel to cut through material and separate it into two pieces. Cutoff operations require self-sharpening wheels.

cylindrical grinders

A machine used to grind round, tapered, or angled features on a cylindrical workpiece. Cylindrical grinders can be controlled manually or by CNC.

dead

A type of center with no moving parts. Dead centers used in cylindrical grinding require the use of a drive plate to rotate the workpiece.

deflecting

Deviating from a straight line or plane when a force is applied. Deflection is more common in long, thin workpieces reacting to the force of the grinding wheel.

dial indicator

A measuring instrument with a contact point attached to a spindle and gears that move a pointer on the dial. Dial indicators are used to check center alignment.

diameter

The distance from one edge of a circle to the opposite edge through the center. The diameter divides a circle in half.

diamond

A superabrasive material that occurs naturally and is also manufactured. Diamond has excellent thermal conductivity.

diamond dresser

A tool that uses one or more diamonds to remove material from the surface of a grinding wheel. Diamond dressers are used to true and dress a grinding wheel.

dressing

Removing swarf and dull grains from the periphery of the grinding wheel by fracturing away the wheel surface. Dressing also sharpens the grinding wheel so that it can achieve proper surface finish on a workpiece.

drive dog

A device that clamps onto a workpiece and transmits turning motion from the headstock, allowing a workpiece to be mounted between centers. Drive dogs are attached to drive plates with dead centers.

drive plate

A device used in combination with dead centers in center-type cylindrical grinding in order to rotate the workpiece. Drive plates attach to the headstock.

electroplated

A coating method that uses electricity and a conductive solution to deposit a layer of plating metal on a metallic or non-metallic workpiece. Electroplating is used to create superabrasive grinding wheels.

feed rate

The rate at which the grinding wheel and the workpiece move in relation to one another. The feed rate describes how far the grinding wheel moves in to the workpiece.

fine

Small grains in an abrasive tool. Fine grains produce tight tolerances and refined surface finishes.

finishing

A grinding process that achieves the required size and surface finish of the part. Finishing operations require precisely balanced wheels.

fixtures

A device that supports the workpiece during grinding. Fixtures on a cylindrical grinder include chucks, centers, and center rests.

flange

A thick, flat metal ring that helps to center the grinding wheel on the wheelhead spindle. A flange can hold moveable weights to help balance a grinding wheel.

fracture

The breaking apart of an abrasive grain in a grinding wheel. Fracturing is part of the wheel's self-sharpening process.

friability

The ability of an abrasive grain to fracture and self-sharpen under stress. The necessary friability properties of an abrasive depend on the workpiece material and workpiece dimensions.

gage block

A hardened steel block that is manufactured with highly accurate dimensions. A gage block can be used to check the angle of a wheelhead or headstock when setting up a cylindrical grinder for taper grinding.

glaze

A smooth, flat surface on the periphery of a grinding wheel. A glazed wheel can occur when grinding a hard workpiece with a hard grinding wheel.

grade

The strength of the bond material in an abrasive wheel. The grade determines many grinding wheel properties.

grain size

The size of an individual abrasive grain in a grinding wheel. Grain size helps to determine the tolerance and surface finish that the wheel can create.

grinding fluid

A liquid used during grinding to clean, cool, and lubricate the grinding wheel and workpiece. Grinding fluid, also known as coolant, helps to prevent a loaded or clogged grinding wheel.

grinding variables

The measureable rates of movement of the abrasive grinding wheel with respect to the workpiece. Grinding variables in cylindrical grinding include speed, feed, and depth of cut.

grinding wheel

A wheel made of bonded abrasives that rotates against a workpiece to remove small chips of material. Grinding wheels in cylindrical grinding use their periphery to grind.

hard

The ability to resist penetration or scratching. A hard abrasive grain does not break down easily.

headstock

The component on a cylindrical grinder that contains a spindle and a drive motor that rotates the workpiece. The headstock has a 90° range of motion.

ID grinding

Inside-diameter grinding. Finishing the interior of a workpiece hole. ID grinding requires chucks or collets to hold the workpiece during grinding.

inert

The state of being non-reactive. Inert materials in vitrified bonds help the grinding wheel to withstand chemicals used in grinding.

infeed

How far the grinding wheel moves into the workpiece. Infeed can be controlled by using the crossfeed handwheel.

inside-diameter grinding

ID grinding. Finishing the interior of a workpiece hole. Inside-diameter grinding requires chucks or collets to hold the workpiece during grinding.

inside-diameter wheels

ID wheels. Grinding wheels that are designed for grinding operations on the inside of a workpiece hole. Inside-diameter wheels are much smaller than outside-diameter wheels and may include different shapes.

jaws

A holding device on a chuck that clamps down on a workpiece. Jaws can be fixed or adjustable.

live

A type of center that uses bearings or friction so that the center rotates with the workpiece. Live centers are used with drive dogs in center-type cylindrical grinding.

locknuts

A threaded fastener that remains tightly in place under vibrations. Locknuts on a cylindrical grinder wheelhead can be manually loosened for grinding tapers or other angled features.

machine guards

A rigid shield over a hazardous area on a machine that prevents debris, such as chips and wheel fragments, from exiting the machine during operation. Machine guards often partially cover the point of operation while still allowing necessary access.

manual cylindrical grinders

A cylindrical grinder that is controlled by the actions of a machine operator, rather than by a Programmable Logic Controller (PLC). Manual cylindrical grinder operators need to follow setup procedures.

material removal rate

The amount of material removed from a workpiece in one cubic inch per minute. Material removal rates can fluctuate depending on the type of abrasive in the grinding wheel, grinding speed, and other factors.

matrix

A mold in which materials are shaped. A solid matrix of metals and abrasives forms a metal-bonded grinding wheel.

metal bonds

A type of bond material deposited on a metal-core wheel with a single layer of superabrasive material. Metal bonds result in wheels with long performance lives.

meters per second

m/s. A measurement of speed that specifies the number of meters that a location on a rotating component travels in one second. Meters per second is used to measure work speed and wheel speed.

mounted points

Smaller grinding wheels that are bonded onto a metal bar or rod. Mounted points are used for finishing smaller holes in a workpiece.

Occupational Safety and Health Administration

OSHA. The federal agency that enforces workplace safety and health legislation in the United States. The Occupational Safety and Health Administration helps employers reduce injuries, illnesses, and deaths in the workplace.

outside-diameter grinding

OD grinding. Grinding that occurs on the external surface of a cylindrical part. Outside-diameter grinding includes center-type and chucking-type grinding.

outside-diameter wheels

OD wheels. A grinding wheel that is designed for grinding the external surface of a workpiece. Outside-diameter wheels are larger than inside-diameter wheels.

peripheral speed

The distance that a given point on the perimeter of a rotating circular object travels, expressed in feet or meters per minute. Peripheral speed is used to describe wheel and work speed in cylindrical grinding.

periphery

The perimeter of an object. The periphery of the grinding wheel in cylindrical grinding feeds into the workpiece surface.

personal protective equipment

PPE. Safety equipment that machine operators wear or use to prevent injury in the workplace. Personal protective equipment includes safety glasses and protective gloves.

phenolic resin

A synthetic, strong plastic made from the reaction between an organic compound and a petroleum-derived compound. Phenolic resin provides resinoid-bonded wheels with flexibility and strength.

plane

An imaginary two-dimensional surface that extends infinitely in any direction in three dimensions. A plane is perfectly flat.

plastic

A lightweight polymer material that has high corrosion resistance, a high strength-to-weight ratio, and a low melting point. Plastic workpieces require a hard and brittle abrasive grinding wheel.

plunge grinding

A type of cylindrical grinding in which the grinding wheel is fed radially into the workpiece, towards its axis. Plunge grinding uses a continuous infeed.

porosity

The relative number of openings or voids in a material. Porosity of a grinding wheel facilitates good coolant application during grinding.

radius truing attachment

A cylindrical grinder accessory that produces concave or convex features on a grinding wheel. A radius truing attachment is mounted on the machine table and has a diamond dresser.

recessed wheel

An abrasive wheel that has an indented area around the wheel center on one or both sides. Recessed wheels may also be relieved wheels.

relieved wheels

A disk-shaped abrasive wheel that angles in towards its center on one or both sides. Relieved wheels provide clearance between the workpiece and the grinding wheel.

resinoid bonds

A bond material formed from a phenolic resin that removes workpiece material at a fast rate and creates fine surface finishes. Resinoid bonds provide flexibility to the grinding wheel.

ring test

A manual test used to detect damage or cracks in grinding wheels. A ring test should be performed prior to using a grinding wheel.

roughing

A grinding process with a high material removal rate. Roughing processes grind a workpiece close to its finished size but without regard for surface finish.

rubber bonds

An organic bond material used to hold abrasive grains together in grinding wheels. Rubber-bonded wheels offer smooth surface finishes.

safety glasses

Protective eyewear with impact-resistant lenses that shield the eyes from flying debris. Safety glasses should be worn during machine setup and operation.

setup

The series of tasks necessary to prepare for processing a workpiece. Setup includes preparing machines, adjusting workholding devices or tooling, and safeguarding machine elements to ensure proper and safe operation.

silicon carbide

A chemical compound made from silicon and carbon with high thermal conductivity. Silicon carbide grinding wheels are hard and brittle.

sintering

Pressing and heating powdered materials close to their melting point to create a solid shape. Sintered metals can be used to form grinding wheels with metal bonds.

speed

The rate at which a grinding tool or workpiece rotates. Speed rates depend on workpiece material, the maximum operating speed of the grinding wheel, and other factors.

spindle

A rotating component on a machine. Spindles on a cylindrical grinder headstock and wheelhead provide rotation for machine components.

steady rest

A cylindrical grinder accessory that supports the workpiece to prevent deflection. Steady rests are also known as universal back rests.

straight wheels

A flat, disk-shaped abrasive wheel. Straight wheels are common abrasive wheels used in cylindrical grinding.

structure

The spacing of the grains and bond material in a grinding wheel. Structure depends on the method used to create the porosity within the grinding wheel.

superabrasive

A type of abrasive with superior hardness and wear resistance. Superabrasives include cubic boron nitride and diamond.

surface feet per minute

sfm. A measurement of speed that specifies the number of feet that a location on a rotating component travels in one minute. Surface feet per minute is used to measure work speed and wheel speed.

surface finish

The texture of a part after it has gone through the grinding process. Surface finish is key to the performance of a finished part.

surface finishes

The texture of a part after it has gone through the grinding process. Surface finish is key to the performance of a finished part.

swarf

The gritty combination of chips, abrasive grains, and worn bonding material produced during grinding. Swarf can clog a grinding wheel and cause it to function improperly.

synthetic

A material produced through deliberate processes rather than natural origins. Synthetic materials are artificial or human-made.

table

The part of the grinding machine that directly or indirectly supports the workpiece. On a cylindrical grinder, the table is often divided into a swiveling lower portion and sliding upper portion.

table reverse dogs

A control on a cylindrical grinding machine that reverses the direction of table movement at the end of each table traverse. Table reverse dogs control the length of the table traverse and can be set manually.

tailstock

A component on a cylindrical grinder located opposite the headstock that supports the far end of the workpiece. The tailstock can move towards and away from the headstock to accommodate different workpiece dimensions.

taper alignment pin

A metal peg or dowel that fits into a machine hole to ensure that two machine components are correctly positioned in relation to one another. Taper alignment pins in the headstock should be removed before adjusting the headstock.

tapered

A gradually decreasing diameter, similar to the shape of a cone. Tapering operations require operators to swivel the machine headstock or wheelhead to grind on a steep angle.

tensile strength

A material's ability to resist forces that attempt to pull it apart or stretch it. The tensile strength of a workpiece determines the necessary abrasive grain of the grinding wheel.

test bar

A device that tests the height of an object for alignment. Test bars are used with dial indicators to check center alignment in cylindrical grinding.

thermoset plastic

A type of strong plastic with high heat-resistance. Thermoset plastics used in resinoid bonds allow the abrasive grains to be released instead of fracturing.

titanium

A strong but lightweight metal. Titanium workpieces can be ground using a silicon carbide grinding wheel.

tolerance

The allowable deviation from a given dimension that will still allow the part to perform its desired function. Tolerances indicate the allowable difference between a physical feature and its intended design.

tool life

The length of time that a grinding tool can function properly before it begins to fail. Tool life can be lengthened by setting safe grinding variables in cylindrical grinding.

tool steel

A steel alloy that has excellent strength, toughness, and wear resistance at high temperatures. Tool steel workpieces require a grinding wheel with hard, abrasive grains.

tough

The ability of a material to absorb energy or force without breaking or fracturing. Toughness determines the ability of a grinding wheel to withstand stress.

traverse grinding

A type of cylindrical grinding in which the sliding table carries the workpiece back and forth across the grinding wheel. Traverse grinding uses an incremental infeed.

traverse length

The linear distance that the sliding table on a grinding machine travels so that the grinding wheel can grind the full length of the part. Traverse length can be automatically set in traverse grinding.

truing

An operation that restores the periphery of the grinding wheel so that it runs radially "true" to the spindle center. Truing can also be used to create a specific wheel profile.

types

A number used to identify a specific grinding wheel shape. Wheel type is often used to specify wheel shape in grinding wheel catalogs.

universal back rest

A cylindrical grinder accessory that supports the workpiece to prevent deflection. Universal back rests are also known as steady rests.

universal cylindrical grinder

A manual cylindrical grinder with a pivoting headstock and wheelhead. A universal cylindrical grinder can perform outside- and inside-diameter grinding.

upper table

The portion of the cylindrical grinding machine table that is mounted on the sliding table. The upper table can swivel to grind tapers and irregular shapes, or it can be locked securely in place.

vitrified bonds

A clay or ceramic bond material characterized by its strength, rigidity, and resistance to oils, water, and temperature changes. Vitrified bonds can fracture to expose new, sharp grains on a grinding wheel.

voids

An empty space between abrasive grains on a grinding wheel. Voids can fill up with chips and swarf during grinding, which reduces grinding wheel efficiency.

wheel guards

A protective cover secured over a grinding wheel to protect workers from broken wheels or debris. Wheel guards are required by OSHA.

wheel speed

The peripheral speed of the grinding wheel. Wheel speed is set faster than work speed.

wheelhead

The part of the grinding machine on which the wheel is mounted. The wheelhead on a cylindrical grinder contains the grinding wheel, grinding wheel spindle, and a drive motor.

wheelhead spindle

The component of a grinding machine that rotates the wheel. The wheelhead spindle can be damaged by excess vibration.

work rests

A fixture on a cylindrical grinder that provides support to a workpiece during grinding. Work rests include center steady rests and universal back rests.

work speed

The peripheral speed of the workpiece. The work speed is set in relation to the wheel speed.

workholding

A device used to support, locate, and hold a workpiece during grinding. The workholding device establishes a relationship between the grinding wheel and the workpiece.