Machining is subtractive manufacturing. You start with solid material and remove everything that is not the part. Nearly every metal component in a vehicle, an aircraft, or an injection mold began as a bar, a casting, or a plate cut down to a print.
The vocabulary matters more than owners expect. Process names such as turning, milling, boring, and EDM describe what happens at the cutting edge. Machine names such as lathe, VMC, boring mill, and wire EDM describe the iron that performs it. Buyers, appraisers, and riggers all speak in those categories, so an accurately described machine draws a serious offer instead of a cautious guess.
Turning: The Workpiece Spins, the Tool Cuts
In turning, the part rotates and a single-point tool moves against it. It is how round features get made: shafts, bushings, fittings, bearing journals. The same setup handles facing, grooving, threading, boring the inside diameter, and parting off, and because the part spins against a fixed tool it holds roundness naturally.
Production turning runs on CNC turning centers: a spindle with a chuck or collet, one or more turrets, often a tailstock. Live tooling and a Y axis let the machine mill and drill without a second setup, and a sub-spindle finishes the back of the part in the same cycle. Swiss-type lathes use a sliding headstock and guide bushing to support long, slender parts right at the cut, which is why they dominate small bar-fed work. A part large in diameter but short goes on a vertical turret lathe. MTE buys all of it: sell your CNC lathe, sell your turning center, or sell your VTL.
Milling: The Tool Spins, the Part Is Clamped Down
Milling is the opposite arrangement. The cutter rotates in a spindle and the workpiece is fixed to a table that moves beneath it. It makes flat faces, slots, pockets, contours, and any surface that is not a body of revolution, which is most of what a general job shop produces.
A vertical machining center, or VMC, puts a vertical spindle over a fixed table. It is versatile, quick to set up, and easy to staff, which is why VMCs fill so many shop floors. A horizontal machining center, or HMC, lays the spindle on its side so chips fall away from the cut, and it runs tombstones on pallet changers for unattended cycles. Five-axis machines add two rotary axes so a complex part finishes in one setup. Gantry and bridge mills carry the spindle over large plate and mold bases. You can sell your VMC, sell your HMC, sell your 5-axis machine, or sell your CNC mill.
Drilling: Making the Hole
A rotating drill feeds along its own axis and leaves a hole that is round, roughly on axis, and roughly on size. Drilling is fast and it is everywhere, but it is a roughing operation. A drilled hole is not a precision hole, which is why tapping and reaming usually follow.
Drill presses and radial arm drills handle straightforward hole-making. Drilling and tapping centers are the CNC version: modest travels, very quick tool changes, a small footprint, built for high-volume hole work. When depth runs many times the diameter, the job moves to a deep-hole machine with high-pressure coolant through a gundrill or BTA tool. You can sell your drilling and tapping center or sell your deep hole drill.
Boring: Making the Hole Right
Boring enlarges and corrects a hole that already exists, and this is the distinction owners blur most often. Drilling creates the hole; boring makes it the right size, round, straight, and correctly located relative to everything else on the part. A single-point boring tool sweeps the bore on its own axis rather than following the errors the drill left behind.
Large housings, gearboxes, and heavy weldments live or die on bore accuracy, which is why horizontal boring mills are their own machine class rather than a milling accessory. They come as table type and floor type, depending on whether the part rides a rotary table or the column travels to the part. This is heavy, long-lived iron, and it is a category MTE buys: sell your boring mill.
Grinding: Abrasive Cutting for Tolerance and Hardness
Grinding replaces one defined cutting edge with thousands of abrasive grains bonded into a wheel, each taking a very small bite. It is where a shop goes when the print calls for tolerances and finishes that turning and milling cannot hold, and it is usually the only practical way to bring hardened steel to size after heat treat.
The family splits by what is being ground. Surface grinders flatten. Cylindrical grinders true outside and inside diameters. Centerless grinders run round parts at volume with no fixturing per part. Tool and cutter grinders sharpen and form the cutting tools themselves, and gear grinders finish tooth forms after heat treat. You can sell your CNC grinder, sell your cylindrical grinder, or sell your tool and cutter grinder.
EDM: Cutting With Controlled Sparks
Electrical discharge machining applies no mechanical cutting force. A controlled spark jumps between an electrode and the workpiece inside a dielectric fluid and erodes material one microscopic crater at a time. Because the mechanism is electrical, EDM does not care how hard the material is, only that it conducts.
Wire EDM pulls a thin brass wire through the part like a bandsaw blade that can turn corners, cutting sharp profiles, tight inside radii, tapers, and stacked plates. Sinker EDM, also called ram EDM, burns a shaped graphite or copper electrode into the part to produce blind cavities, ribs, and detail no rotating cutter could reach. Small-hole EDM drills start holes and cooling passages. Die, mold, and aerospace tooling shops depend on all three. Start here to sell your wire EDM or sell your EDM machine.
The Rest of the Floor
Multi-tasking or mill-turn machines combine a turning spindle with a milling head on a B axis and finish complicated parts complete in one setup. Gear equipment hobs, shapes, shaves, and grinds tooth forms. Saws cut stock to length, and lasers, waterjets, and plasma tables profile sheet and plate. MTE buys these too: sell your multi-tasking machine, sell your gear machine, sell your band saw, or sell your laser cutter.
Tooling: The Part That Actually Cuts
The machine supplies motion and rigidity. The tool does the cutting.
Indexable carbide inserts do the bulk of production turning and face milling. An insert is defined by shape, size, nose radius, chipbreaker geometry, carbide grade, and coating, and matching those to the material separates a good finish from scrap. Solid-carbide end mills handle profiling and pocketing. Twist drills and gundrills cover hole-making, taps and thread mills cut threads, and reamers and boring heads finish holes to size. Grinding runs bonded wheels in aluminum oxide, silicon carbide, CBN, or diamond.
Everything mounts through a toolholder, and the spindle interface is a real specification. CAT 40 and CAT 50, BT 30 through BT 50, HSK, and polygonal taper systems are not interchangeable, and inside them sit ER collet chucks, shrink-fit holders, and hydraulic chucks. Spindle taper matters on resale for a plain reason: the next owner's holders either fit the machine or they do not. If a tooling package or a full magazine of holders goes with the machine, write it down. The same goes for inspection gear, the last thing anyone thinks about during a clearance.
Workholding: How the Part Is Held Still
Cutting forces have to be resisted by something. On a lathe that means a three-jaw chuck with hard or soft jaws, a four-jaw chuck for off-center work, a collet chuck for small round stock, a tailstock center and steady rest for long parts, and a bar feeder for continuous production.
On a machining center it means a precision vise, a fixture plate, or a tombstone bolted to an HMC pallet so several parts index into the cut. Rotary tables and trunnions add a fourth or fifth axis to a machine that did not ship with one, and zero-point pallet systems and robot cells shorten the gap between cycles. Grinding leans on magnetic chucks and work rests, and EDM shops standardize on reference tooling so an electrode returns to a known position every time.
Rotary tables, bar feeders, pallet systems, and automation cells are separately valuable. Inventory them rather than assuming they stay with the building.
The Control, and Why It Matters on Resale
The CNC control is not an afterthought when a machine changes hands. Some builders write their own: Okuma runs OSP, Haas runs its own control, and Mazak's Mazatrol is a conversational system machinists either know well or do not. Many other builders ship a Fanuc or a Siemens Sinumerik control on their own iron, and Heidenhain, Mitsubishi, Fagor, and Brother all carry installed bases of their own.
The control determines who can walk up and run the machine, what service and parts are available, and how easily it connects to current programming systems. Name the control and its generation alongside the builder, model, and year. It is one of the first things a buyer asks.
How These Categories Map to What MTE Buys
Machine Tool Exchange buys used CNC machines outright, directly from the companies that own them, in all 50 states. MTE is not a broker, not a consignment service, and not a listing marketplace. MTE is the buyer, so there is no listing period, no commission, and no auction wait, and MTE arranges and pays for the rigging and freight. If your machine is not named above, that does not mean MTE will not buy it. Call 800-822-9524, or start at the sell your machine page.
What to Have Ready Before You Call
A quote is only as good as the description. Gather this before you call:
- Builder, model, and year off the nameplate, not from memory
- Control make and generation
- Spindle taper and max RPM, plus spindle hours if the control reports them
- Axis travels and table size for a mill, or swing, chuck size, and bar capacity for a lathe
- Options: tool magazine, pallet count, fourth or fifth axis, bar feeder, probing, through-spindle coolant, chip conveyor
- Tooling, holders, fixtures, and workholding included in the sale
- Current state: cutting parts, under power but idle, or decommissioned, and any known faults
- Maintenance history: ballscrew or way work, rebuilds, control retrofits
- Photos of the machine, the control screen, and the nameplate
- Location, plus dock, door, and floor access so the riggers can plan
A machine described precisely is a machine a buyer can price with confidence. When it is time to move equipment, call 800-822-9524 or submit your machine details, whether it is one idle machine in the corner or a full floor coming out during a plant move.