machining Machining is a manufacturing process where a desired shape or part is created using the controlled removal of material, most often metal, from a larger piece of raw material by cutting. Machining is a form of subtractive manufacturing, which util ...

, facing is the

cutting Cutting is the separation or opening of a physical object, into two or more portions, through the application of an acutely directed force. Implements commonly used for wikt:cut, cutting are the knife and saw, or in medicine and science the sca ...

of a flat surface

perpendicular In geometry, two geometric objects are perpendicular if they intersect at right angles, i.e. at an angle of 90 degrees or π/2 radians. The condition of perpendicularity may be represented graphically using the '' perpendicular symbol'', � ...

to some axis of the

workpiece A workpiece is a piece, often made of a single material, that is being processed into another desired shape (such as building blocks). The workpiece is usually a piece of relatively rigid material such as wood, metal, plastic, or stone. After a ...

. This can be applied in two different areas: *Facing on a

milling machine Milling is the process of machining using rotary cutters to remove material by advancing a cutter into a workpiece. This may be done by varying directions on one or several axes, cutter head speed, and pressure. Milling covers a wide variety of ...

(perpendicular to the axis of movement), which involves various milling operations, but primarily face milling. *Facing on a

lathe A lathe () is a machine tool that rotates a workpiece about an axis of rotation to perform various operations such as cutting, sanding, knurling, drilling, deformation, facing, threading and turning, with tools that are applied to the w ...

(perpendicular to the axis of rotation), which is commonly used in

turning Turning is a machining process in which a cutting tool, typically a non-rotary tool bit, describes a helix toolpath by moving more or less linearly while the workpiece rotates. Usually the term "turning" is reserved for the generation of ...

and boring operations. Other operations remove material in ways similar to facing, for example, planing, shaping, and grinding, but these processes are not labeled by the term "facing."

Facing lathe operation

Facing on the lathe uses a facing tool to cut a flat surface perpendicular to the work piece's rotational axis. A facing tool is mounted into a tool holder that rests on the carriage of the

. The tool will then feed perpendicularly across the part's rotational axis as it spins in the jaws of the chuck. A user will have the option to hand feed the machine while facing, or use the power feed option. For a smoother surface, using the power feed option is optimal due to a constant feed rate. Facing will take the work piece down to its finished length very accurately. Depending on how much material needs to be taken off, a

machinist A machinist is a tradesperson or trained professional who operates machine tools, and has the ability to set up tools such as milling machines, grinders, lathes, and drilling machines. A competent machinist will generally have a strong mechan ...

can choose to take roughing or finishing cuts. Factors that affect the quality and effectiveness of facing operations on the lathe are

speeds and feeds The phrase speeds and feeds or feeds and speeds refers to two separate parameters in machine tool practice, cutting speed and feed rate. They are often considered as a pair because of their combined effect on the cutting process. Each, however, ...

, material

hardness In materials science, hardness (antonym: softness) is a measure of the resistance to plastic deformation, such as an indentation (over an area) or a scratch (linear), induced mechanically either by Pressing (metalworking), pressing or abrasion ...

, cutter size, and how the part is being clamped down.

Face milling operation

Facing on a

is the process of cutting a flat surface perpendicular to the axes of the

milling cutter Milling cutters are cutting tools typically used in milling machines or machining centres to perform milling operations (and occasionally in other machine tools). They remove material by their movement within the machine (e.g., a ball nose mill) ...

. This process removes the material by rotating the facing tool in the counterclockwise direction as the table feeds the work piece across the cutter. Face milling can be achieved with an end mill, but is often done with a face mill, shell mill or a fly cutter. Face milling can be done in both manual machining and CNC machining. To obtain a smoother surface finish it is best to let the machine feed the table. Newer manual milling machines and CNC machines will have this option, but older milling machines will not. Hand feeding the table will allow human error into the process. Machinists also have the option to take roughing cuts and finish cuts. Factors that affect the quality and effectiveness of facing operations on the mill are

, material

, cutter size, and how the part is being clamped down. Spotfacing is the facing of spots (localized areas), such as the bearing surfaces on which bolt heads or

washers Washer most commonly refers to: *Washer (hardware), a thin usually disc-shaped plate with a hole in the middle typically used with a bolt or nut *Washing machine, for cleaning clothes Washer may also refer to: *Dishwasher, a machine for cleani ...

will sit.

References

{{reflist Machining