Grinding Processes 201
Grinding Processes provides a comprehensive overview of the various types of grinding used in modern manufacturing environments. Surface, cylindrical, centerless, and internal grinding processes are commonly used for workpieces of various shapes. Surface grinding is further distinguished by whether the table is rotary or reciprocating, and whether the spindle is vertically or horizontally oriented. Cylindrical grinding is distinguished by workholding, whether center-type or chucking-type. Centerless grinding can be either throughfeed or infeed, and internal grinding can be done on a cylindrical or centerless grinder.
A foundational knowledge of the different types of grinding, including how they operate and what types of workpieces they are appropriate for, is necessary for any further learning or training in grinding. This class introduces students to the various types of grinding that they may encounter, describing both machine tools and movements.
Number of Lessons 18
- The Importance of Grinding
- Types of Grinding Machines
- Surface Grinders: Reciprocating and Rotating Tables
- Horizontal-Spindle Surface Grinders
- Vertical-Spindle Grinding
- Creep-Feed Grinding
- Cylindrical Grinding
- Center-Type OD Grinding
- Chucking-Type OD Grinding
- Internal Grinding
- Internal Chuck Grinding
- Centerless Grinding
- Centerless Grinding in Action
- Infeed Centerless Grinding
- Internal Centerless Grinding
- Final Review
- Describe the benefits of grinding.
- Describe basic types of grinding machines.
- Describe the basic elements of surface grinders.
- Describe horizontal-spindle surface grinders.
- Describe vertical-spindle surface grinders.
- Describe creep-feed grinding.
- Describe cylindrical grinding.
- Describe center-type OD grinding.
- Describe chucking-type OD grinding.
- Describe internal diameter grinding.
- Describe internal chuck grinding.
- Define centerless grinding.
- Describe throughfeed centerless grinding.
- Describe infeed centerless grinding.
- Describe internal centerless grinding.
A wheel composed of abrasive grains held together in a bond. Abrasive wheels are used in grinding operations.
A grinding machine that can perform multiple grinding cycles, independent of an operator. Automatic grinders are often available with CNC.
A common name for vertical-spindle surface grinders using a rotating table and cup-shaped grinding wheel. Blanchard grinding can reduce production times by grinding multiple workpieces simultaneously.
Held together in a substance. Bonded grinding wheels can be held together by a number of materials including fused clay, resin, shellac, and rubber.
The interior diameter of a cylinder. Bore surfaces are often accurately ground through ID grinding.
A pointed cylindrical component used to hold one end of a workpiece by inserting the tip into a matching hole in the workpiece. Centers are used during cylindrical grinding to mount and rotate cylindrical parts against the grinding wheel.
A type of cylindrical grinding in which the workpiece is not supported on a spindle. Centerless grinding supports workpieces on a work-rest blade that guides them between a grinding wheel and a regulating wheel.
center-type cylindrical grinding
A type of cylindrical grinding in which the workpiece is held and rotated by centers on each end. Center-type cylindrical grinding allows for grinding the entire length of a workpiece.
A workholding device with three or four adjustable jaws that holds a workpiece as it rotates. A chuck secures the workpiece on one end.
chucking-type cylindrical grinding
A type of cylindrical grinding in which one end of the workpiece is held and rotated in a chuck. Chucking-type cylindrical grinding is not as precise as the center-type.
A workholding device composed of segments that tighten around a center hole with a fixed size. A collet allows for more precision than a chuck.
computer numerical control
CNC. A type of programmable automation, directed by mathematical data, which uses computers to carry out various machining operations. CNC is a self-contained system that executes program instructions to guide machine tool components.
To be circular or to share the same center. Concentric workpieces have a very even, symmetrical shape.
A grinding method in which the depth of cut is increased while the feed rate is decreased. Creep-feed grinding removes a greater amount of material in one pass than standard surface grinding operations.
A single increment of something that happens repeatedly. A cycle involves every step of grinding a part including setting the part, grinding it, and removing it from the machine.
A grinding process used in grinding cylindrical workpieces. In cylindrical grinding both the grinding wheel and a cylindrical workpiece are rotated together.
depth of cut
The amount of material removed by one pass of the cutting tool. Depth of cut also refers to how far a grinding wheel plunges into the workpiece.
The distance from one edge of a circle, through its center, to the opposite edge. Diameter measures the width of a circle.
The desired measurement of a part. Dimensions encompass every measurement of a part, including length, width, and height.
The component of a grinding machine that moves the grinding wheel downward into the workpiece material. Downfeed mechanisms may be manual as well as automated.
The process by which a tool is used to sharpen a grinding wheel. Dressing works by removing a layer of dull grains from the wheel, revealing fresh, sharp grains.
A device that stops a workpiece from passing all the way through the regulating and grinding wheels in infeed centerless grinding. Some end-stops eject the workpiece when grinding is finished.
The broad surface of a grinding wheel. The face is used for large material removal or to finish a wide surface area.
The method of advancing parts into a machine, either automatically or by hand. Different feed methods are required for various grinding processes.
The rate at which the grinding wheel and the workpiece move in relation to one another. The feed rate in creep-feed grinding is slower than in conventional grinding.
The final cuts taken with a grinding wheel to obtain the accuracy and surface finish desired. Finishing often requires faster work speeds.
formed grinding wheel
A grinding wheel shaped to create specific features on a workpiece. Formed grinding wheels can be used to produce grooves on a workpiece.
The use of an abrasive to cut the surface of a workpiece and change its shape. Grinding operations commonly use abrasive grains bonded into a wheel shape.
A liquid used to cool and lubricate the grinding wheel and workpiece during grinding. Grinding fluids can be composed of water, oil, or synthetic compounds, depending on the needs of the process.
horizontal-spindle surface grinders
A grinding machine with the grinding wheel mounted on a spindle parallel to the worktable. Horizontal-spindle surface grinders typically grind on the wheel's periphery.
A form of fluid dynamics that uses the motion and pressure of liquids to create power. Hydraulic power uses cylinders and pistons to convert the flow of liquids into mechanical energy.
infeed centerless grinding
A centerless grinding process for cylindrical workpieces with varying diameters. Infeed centerless grinding uses an end-stop to prevent the workpiece from passing completely over the grinding wheel.
internal centerless grinding
A grinding process in which a cylindrical workpiece is supported and rotated by two rollers and a regulating wheel with the grinding wheel inside the workpiece to shape and finish its inner sides. Internal centerless grinding creates close concentricity between the interior and exterior of a workpiece.
internal chucking-type grinding
A grinding process in which the workpiece is held firmly by a chuck on one end with the grinding wheel inserted into the other to shape and finish its inner sides. Internal chucking-type grinding is the most common type of ID grinding.
ID. A type of grinding performed on the interior surface of a cylindrical workpiece. Internal diameter grinding produces precision holes in a workpiece.
magnetic drive plate
A workholding device that uses a magnetic metal plate to rotate a cylindrical workpiece. A magnetic drive plate controls workspeed in place of a regulating wheel.
A material that creates a magnetic field which attracts iron and other magnetic substances to it. Magnets are used as workholding devices in surface grinding.
A grinding machine that requires an operator to control every part of the grinding process. Manual grinders include smaller, hand-held machines.
Outside diameter grinding. A type of grinding performed on the exterior cylindrical surface of a workpiece. OD grinding creates a concentric surface on a cylindrical workpiece.
outside diameter grinding
OD. A type of grinding performed on the exterior cylindrical surface of a workpiece. Outside diameter grinding creates a concentric surface on a cylindrical workpiece.
The outermost edge of an object. The periphery of a grinding wheel is used for precise cuts.
A form of fluid dynamics that uses the motion and pressure of gas, usually compressed air, to create power. Pneumatic power converts the potential energy of pressurized gas into mechanical energy.
A grinding method that uses specifically shaped grinding wheels. Profile grinding shapes and finishes workpieces with complex shapes or diameters.
To repeatedly move back and forth. Typical reciprocating tables move in a side-to-side motion against a grinding wheel.
Commonly made of plastic or rubber bond, this wheel is used to rotate the workpiece and pull it through the operation. A regulating wheel is also known as a feed wheel.
To move in a circle. Typical rotating tables move in a circular motion against a grinding wheel.
A grinding machine that performs a grinding cycle independently, but requires an operator to set and start the process. Semi-automatic grinders grind a workpiece automatically, but require an operator to set and remove the part.
A metal block used to locate and support a workpiece in centerless grinding. Two grinding shoes take the place of a work-rest blade and regulating wheel typically found in centerless grinding.
A spinning or rotating component of a machine tool. The spindle holds the grinding wheel and possibly the workholding device on the grinding machine.
A common grinding process that uses a rotating grinding wheel to cut away precise amounts of a flat workpiece surface. Surface grinding is often one part of a sequence of machining operations.
The part of the grinding machine that directly or indirectly supports the workpiece. The table may rotate or reciprocate in surface grinding.
A method of centerless grinding in which the regulating wheel and work guides feed the workpiece past the grinding wheel in a straight line. In throughfeed grinding, the regulating wheel moves the part completely past the grinding wheel.
The acceptable variation from a specified dimension. Tolerances represent a part's deviation from its specifications while still allowing it to perform its desired function.
vertical-spindle surface grinders
A grinding machine with the grinding wheel mounted on a spindle perpendicular to the worktable. Vertical-spindle surface grinders typically use the face of the grinding wheel.
A workholding device that uses a pair of tightly clamped jaws to secure a workpiece. Vices keep workpieces from shifting out of place during grinding operations.
A device, often with an angled edge, that supports cylindrical workpieces during centerless grinding. The work-rest blade allows the workpiece to pass through the regulating wheel and grinding wheel, rather than hold it in place like centers or a chuck.