NIMS CNC key terms

A formal safety procedure in which every energy source feeding a machine is shut off, isolated, locked, and tagged before service work begins, so the equipment cannot be restarted by another person.

Safety gear worn by the operator, such as safety glasses, hearing protection, and protective shoes, chosen to reduce exposure to flying chips, coolant, noise, and sharp edges at the machine.

A standardized document supplied with each chemical product, such as coolant concentrate or solvent, listing its hazards, safe handling and storage rules, required protective equipment, and first-aid and spill steps.

A large, clearly marked pushbutton that immediately stops spindle rotation, axis motion, and usually coolant when pressed, used whenever a person or the machine is in immediate danger.

A theoretically exact point, axis, or plane on a drawing from which dimensions and geometric tolerances are referenced; on the part it is established by contact with a surface plate, pin, or fixture.

A rectangular box on a drawing that states a geometric tolerance: the symbol naming the control, the size of the tolerance zone, and the datums that orient or locate that zone.

A geometric control that defines a cylindrical or spherical zone centered on a feature's exact intended location; the feature's actual axis or center point must lie within that zone.

A dimension enclosed in a rectangle with no tolerance of its own; it states an exact theoretical location or size used by a feature control frame, which supplies the actual permissible variation.

A drawing symbol, typically a checkmark carrying a number, that specifies the required roughness of a machined surface, usually as an Ra value, and may also call out a machining method.

A precision hand tool that uses a calibrated screw and spindle to measure outside diameters and thicknesses, commonly reading to 0.001 inch or 0.01 millimeter.

An instrument with a spring-loaded plunger and a graduated dial that displays small linear movement, used to check runout, alignment, flatness, and machine geometry.

The documented comparison of a measuring tool's readings against a traceable reference standard to confirm the tool is within allowed error, performed on a schedule and recorded.

A computer-driven measuring machine that contacts or scans a part with a probe and calculates feature size, location, and geometric tolerance from the collected point coordinates.

The average height of tiny irregularities left on a machined surface, reported in micrometers or microinches; lower values mean a smoother finish, produced by finer feed and sharp tooling.

The rate at which a point on the cutting edge passes through the workpiece material, given in surface feet or meters per minute and converted to spindle rpm using the tool diameter.

The speed at which the cutter advances into the work, programmed in inches or millimeters per minute and derived from feed per tooth, tooth count, and spindle speed.

The thickness of material removed by each cutting edge per revolution, calculated as feed per revolution divided by the number of teeth; it governs chip formation, finish, and tool life.

A replaceable cutting tip of cemented tungsten carbide clamped into a toolholder; inserts come in shapes, grades, and coatings that balance wear resistance against toughness for a given workpiece material.

The tendency of some materials, particularly austenitic stainless steel, to become harder and stronger when rubbed or deformed, so light cuts and steady feed keep the tool cutting instead of rubbing.

The address-letter commands, such as G01 for straight feed or G81 for drilling, that tell a CNC control how to move the axes and which operating modes are active.

A command that operates machine functions other than axis motion, such as spindle on and off, coolant, tool change, and program stop or end, for example M03, M08, or M30.

A command that remains active through later program blocks until it is cancelled or replaced by another command from the same group, as with G01 or G90.

A stored coordinate system that locates the program zero point relative to machine home, letting the same program run on different parts by changing the offset values.

A control feature, G41 for left and G42 for right, that shifts the programmed path by the cutter radius, so the part can be programmed to finished size while the actual tool diameter is entered separately.

Software that turns a CAD model plus selected machining strategies into toolpaths and then, through a post processor, into G-code for a specific machine control.

A software configuration that converts generic CAM toolpath output into the exact G-code format and command dialect required by a particular machine tool and control.

A stored value for each tool describing how far its tip sits from the spindle gauge line, so programmed Z depths come out correct whatever tool is in the spindle.

The setup step of bringing a tool tip to a known reference surface or tool setter to establish its length offset and confirm that programmed depths will be accurate.

The amount by which a rotating tool or part surface deviates from a true circle or true axis, measured with an indicator; excess runout causes chatter, poor finish, and short tool life.

Unhardened, machinable vise or chuck jaws that are bored or cut to fit the workpiece, giving broad contact and protecting finished surfaces while holding the part securely.

A device that locates and clamps a workpiece in a repeatable position relative to the machine axes, so each successive part can be machined without re-indicating.

Running a program with no material being cut, typically with the tool raised or rapids slowed, to confirm axis motion, clearances, and offsets before the first actual cut.

A control mode that runs one program block each time cycle start is pressed, allowing the operator to check each move, offset, and tool change during setup or troubleshooting.

A program command that pauses the cycle only when the optional stop switch is turned on, used to inspect a feature, clear chips, or check a tool partway through the program.

A mechanism that automatically removes the tool from the spindle and replaces it with the next tool from a magazine, applying stored offsets so the correct length is used at every step.

Scheduled servicing such as lubrication, filter and coolant changes, level checks, and cleaning, performed on a calendar or run-hour basis to prevent breakdowns rather than repair them afterward.

Lost motion that occurs when an axis reverses direction because of clearance between the ballscrew and nut; the control can compensate for it, but it grows as parts wear.

The ratio of coolant concentrate to water in the machine's sump, checked with a refractometer; too weak invites rust and poor cooling, while too strong leaves sticky residue.

A structured technique, such as the five whys or a fishbone diagram, that traces a problem back to its underlying cause so a fix prevents repeat occurrences instead of hiding symptoms.