| arbor | The bar attached to the spindle in a horizontal milling machine. The arbor holds the milling cutter. |
| automatic bar machine | A turning machine that continuously cuts a number of parts from a piece of bar stock, one after another. The bar stock advances through the spindle and is held by the collet during the operation. |
| axis | An imaginary straight line that passes through the center of an object. |
| backstroke | The return motion of a saw blade that cuts with a back-and-forth movement. |
| band saw | A long, continuous cutting blade with serrated teeth that is looped around two or more wheels. |
| bar stock | Raw material purchased from metal manufacturers in the form of long bars. |
| base | The foundation of a machine that supports all the other machine components. |
| bed | The main supporting structure upon which the operating parts of the machine are mounted and guided. |
| bed-type milling machine | A type of milling machine used to mill flat surfaces that has a large bed, which only moves along a horizontal axis. |
| broach | A multi-point cutting tool made of a series of progressively smaller teeth that can both remove metal and finish the surface of a workpiece with one pass of the cutting tool. |
| broaching machine | A machine that uses a multi-point cutting tool to shape and finish either the interior of a hole or the surface of a workpiece. |
| carbide insert | A cutting bit made of hard material that has multiple cutting edges. Once a cutting edge is excessively worn, it can be indexed to another edge, or the insert can be replaced. |
| carriage | The section of the lathe that slides back and forth along the ways and supports the cross-slide and cutting tool. |
| center | The device located in the tailstock that holds in place the end of the workpiece opposite the spindle. |
| chip | An unwanted piece of metal that is removed from a workpiece. Chips are formed when a tool cuts or grinds metal. |
| chuck | A device that holds a workpiece in place as it rotates. The chuck commonly has three or four jaws that can be adjusted to fit various sizes. |
| circular saw | A power saw that cuts with a toothed or abrasive disk rotating at high speed. |
| CNC machining center | A sophisticated CNC machine that can perform multiple machining operations in the same setup with a variety of tools. |
| CNC turning center | A sophisticated CNC machine that specializes in turning, boring, drilling, and threading operations, all at the same location. |
| collet | A slitted device that holds a workpiece in place as it rotates. A collet has a hole through which the workpiece passes, and it is designed to hold specific dimensions. Collets can also be used to hold cutting tools. |
| column | The vertical support, or backbone, of a machine. |
| column-and-knee milling machine | A milling machine with a spindle that is mounted in the column and a worktable that rests on an adjustable knee. |
| compound rest | The part of the lathe on the carriage that allows for angular adjustment of the cutting tool. |
| contour | A cutting process that creates a curved, non-linear dimension. |
| countersinking | The cutting of a beveled edge at the end of a hole so that the head of a screw can rest flush with the workpiece surface. |
| cutting | The use of single- or multi- point tools to separate metal from a workpiece in the form of chips. |
| drilling | The use of a rotating drill in order to cut a round hole into a workpiece. |
| drive | The main device that powers the rotation of the spindle. |
| end mill | A thin, tall mill cutter with cutting edges that wind up the sides. Both the bottom and side of the end mill are used during milling operations. End mills resemble drills. |
| engine lathe | The original and most basic type of lathe. |
| face mill | A flat mill cutter with multiple cutting teeth surrounding the tool. The bottom of the face mill is primarily used during milling operations. |
| feed handle | A handle attached to a machine that controls the movement of the cutting tool. |
| finishing tool | A single-point cutting tool used to make a very light cut for final touches to achieve precise tolerances or improved finishes. |
| form mill | A type of milling cutter that is designed in an irregular shape in order to mill contours. |
| hacksaw | A saw that contains a blade made of high-speed steel, molybdenum, or tungsten alloy steel that cuts in one direction. |
| head | The part of a drill press that contains the spindle and the motor. |
| headstock | The end of a lathe that holds the spindle and the drive that rotates the workpiece. |
| high-speed steel | A material used in cutting tools to machine metals at high cutting speeds. High-speed steel stays hard at high temperatures, has great hardness, and is resistant to abrasion. |
| keyway | A rectangular slot or groove that is machined down the length of a hole. |
| knee | The device supported by an elevating screw that raises and lowers and guides the back and forth motion of the saddle. |
| lathe | A machine tool that holds a cylindrical workpiece at one or both ends and rotates it while various cutting tools remove material. Turning is a common operation performed on the lathe. |
| leadscrew | The long, threaded device that controls the precise movement of the carriage on a lathe. |
| machine tool | A power-driven machine that holds a variety of tools. These tools include cutting tools, workholding devices, punches, and other manufacturing tools. |
| machining | The process of removing metal to form or finish a part, either with traditional methods like turning, drilling, milling, and grinding, or with less traditional methods that use electricity, heat, or chemical reaction. |
| mill | A multi-point cutting tool that is used to remove metal from the surface of a workpiece. |
| milling cutter | A rotary cutting tool with teeth around its periphery that is used on milling machines. |
| milling machine | A machine that uses a multi-point tool to remove metal from the surface of a workpiece. |
| multiple spindle drill | A drilling machine that contains two or more spindles, which perform multiple cutting operations at the same time. |
| multi-point tool | A cutting tool that has two or more cutting edges. |
| overarm | The device on a horizontal milling machine that reaches over the workpiece and supports the spindle or arbor. |
| plain mill | A cutting tool for the milling machine with cutting surfaces on the periphery. It is used to mill flat surfaces. |
| planer-type milling machine | A very large type of milling machine that often contains numerous milling heads. |
| plate stock | A flat piece of raw material that is used to make manufactured parts. |
| pocket | An interior recess that is cut into the surface of a workpiece. |
| radial drill | A drilling machine that can accommodate large workpieces by maneuvering an overarm in place over the workpiece. |
| reaming | The use of a multi-point cutting tool to smooth or enlarge a previously drilled hole. |
| reciprocating | The back-and-forth motion of a hacksaw in which only one motion actually contacts and cuts the workpiece. |
| rough cutting | The quick removal of metal from a workpiece without regard to tolerances or finish. |
| roughing tool | A single-point cutting tool used to make very heavy cuts and remove metal as quickly as possible. |
| saddle | The device supported by the knee that slides back and forth on the knee and guides the left and right motion of the worktable. |
| saw | A multi-point cutting device that is used to rough cut a part to a certain length. |
| shell mill | A type of milling cutter that has cutting edges around its periphery and can be mounted on an arbor. |
| side mill | A narrow type of milling cutter that has cutting edges on both its end and periphery. |
| single-point tool | A cutting tool that has a single cutting edge. |
| slab broach | A flat-shaped broach that is used to remove metal from the workpiece surface. |
| spindle | The part of the machine tool that spins. On the mill, the spindle holds a cutting tool. On the lathe, the spindle holds the workpiece. |
| stock | The raw material out of which manufactured parts are made. |
| tailstock | The part located at the end of a lathe opposite the headstock that supports the end of longer workpieces. |
| tapping | The process of cutting internal threads in a workpiece with a multi-point tool. |
| tolerance | The unwanted but acceptable deviation from the desired dimension. |
| t-slot cutter | A type of milling cutter that is used to machine a portion of a T-shaped slot into a workpiece. |
| turning | A machining operation used to make cylindrical parts. A single-point cutting tool passes along the outer surface of a cylindrical workpiece as it rotates, and gradually removes a layer of material. |
| turret | The component of a lathe that holds a number of cutting tools. The turret rotates to place tools in the cutting position. |
| turret lathe | A lathe with a mounted device that holds multiple cutting tools. The turret rotates to position a specific cutting tool in place. |
| vise | A workholding device with one fixed jaw and one moveable jaw. Vises are often used to hold simple rectangular or cubic workpieces on a mill or machining center. |
| ways | Two precisely measured, parallel tracks that support and guide the movement of the carriage and cross slide. |
| workpiece | A part that is being worked on. It may be subject to cutting, welding, forming or other operations. |
| worktable | The part of a machine tool that supports the workpiece and any workholding devices. |
