Used Machinery Glossary

CNC machine terms

CNC (computer numerical control)

CNC is the computer control that moves a machine tool’s axes and spindle from a stored program, usually written in G-code. A CNC machine makes the same part to the same dimensions again and again without an operator guiding each cut. See used CNC machines.

Vertical machining center (VMC)

A vertical machining center is a CNC mill with its spindle mounted vertically above a moving table, used to mill, drill and tap parts held in a vise or fixture. Buyers compare X, Y and Z travels, spindle taper and speed, tool-changer capacity and the control. See used vertical machining centers and the VMC buying guide.

Horizontal machining center (HMC)

A horizontal machining center is a CNC mill with a horizontal spindle, usually a rotating table and a pallet changer, so one pallet is loaded while the other is cut. Chips fall away from the work, which suits long runs and parts machined on several sides. Check pallet size, table indexing and spindle taper. See used horizontal machining centers.

CNC turning center

A CNC turning center is a lathe that spins the workpiece against cutting tools held on a turret. Options decide what it can finish in one setup: live tooling drives rotating tools for milling and drilling, a Y-axis moves them off center, and a sub-spindle machines the back of the part. See used CNC lathes and the CNC lathe buying guide.

Swiss-type lathe

A Swiss-type lathe feeds bar stock through a guide bushing with a sliding headstock, so every cut happens close to a support. That suits long, slender, precise parts such as bone screws and connector pins, usually fed from a bar feeder. See used Swiss lathes and the Swiss lathe buying guide.

Spindle taper

The spindle taper is the cone-shaped socket in the spindle that holds the tool holder. Size 40 tapers cover most machining-center work and size 50 takes heavier cuts. CAT and BT holders of the same size are not interchangeable, and HSK is a different, shorter design, so match the taper to the tooling you already own.

Through-spindle coolant (TSC)

Through-spindle coolant pumps coolant at high pressure through the spindle and out of the tool tip, flushing chips from deep holes and cooling the cutting edge. Common systems run from about 300 to 1,000 psi. On a used machine with TSC, check the pump, filters and rotary union.

EDM (electrical discharge machining)

EDM removes metal with controlled electrical sparks instead of a cutting tool, so it works on hardened steel and carbide. Wire EDM cuts through a part with a thin wire, sinker EDM burns a shaped electrode into it, and a hole-popper EDM drills small starter holes. See used EDM machines.

Fabrication machine terms

Fabrication machines cut, bend, punch and roll sheet, plate and structural steel. Browse used fabrication machinery.

Press brake tonnage

Press brake tonnage is the most bending force a press brake can apply, and its bed length is the longest part it can bend. The force a job needs rises with material thickness, strength and bend length and falls with a wider die opening, so check a bending chart against your thickest work. See used press brakes and the press brake buying guide.

Fiber laser

A fiber laser cutter makes its beam in a solid-state source and carries it by fiber-optic cable to the cutting head. Compared with a CO2 laser it cuts thin and reflective metals such as aluminum, brass and copper faster, with less beam-path upkeep. Power is stated in kilowatts. See used laser cutting machines.

Plasma cutting table

A plasma cutting table cuts electrically conductive metal with an electric arc carried in a jet of ionized gas, while CNC moves the torch over plate lying on the table. It cuts thick steel plate quickly but leaves a wider cut and a rougher edge than a laser. On a used table, check the power source’s amperage, the torch height control and the water or downdraft table. See used plasma cutters and the plasma table buying guide.

Shear

A shear cuts sheet or plate in a straight line by driving a moving upper blade down past a fixed lower blade. Its rating gives the longest cut and the thickest mild steel it can take; stainless and other stronger metals lower that thickness. On a used shear, check the blades, the blade-gap adjustment and the back gauge. See used shears and the shear buying guide.

Abrasive waterjet

An abrasive waterjet cuts by forcing water at tens of thousands of psi through a tiny orifice and mixing in garnet abrasive. It cuts metal, stone, glass and composites without heat, so the edge has no heat-affected zone. On a used waterjet, check the pump type (intensifier or direct drive), its hours and its last rebuild. See used waterjets and the waterjet buying guide.

Turret punch press

A turret punch press punches holes and shapes in sheet metal from a rotating turret of punch-and-die stations while CNC moves the sheet beneath it. Buyers compare tonnage, sheet size, the number of stations and how many of them are auto-index stations that can rotate the tool. See used turret punches.

Plastics machine terms

Plastics machines mold, extrude, form and recycle plastic, and auxiliary equipment keeps the process at temperature. Browse used plastics machinery.

Clamp tonnage

Clamp tonnage is the force an injection molding machine uses to hold the mold shut against injection pressure, and it is the first number buyers match to a mold. Shot size, the amount of plastic injected per cycle, and tie-bar spacing, which limits how wide a mold fits, come next. See used injection molding machines.

Plastic extruder

A plastic extruder melts plastic pellets with a turning screw inside a heated barrel and pushes the melt through a die to make continuous shapes such as pipe, profile, sheet or film. Screw diameter and the L/D ratio, the screw’s length divided by its diameter, set how much it can melt and mix. On a used extruder, check screw and barrel wear, the gearbox and the heater zones. See used plastic extruders and the extruder buying guide.

Thermoforming machine

A thermoforming machine heats a plastic sheet until it softens, then shapes it over or into a mold with vacuum, air pressure or both, and the formed parts are trimmed from the sheet. Cut-sheet machines form one sheet at a time for thicker, larger parts; roll-fed machines run thin sheet from a roll, mostly for packaging. Buyers compare forming area, sheet thickness range and draw depth. See used thermoforming machines.

Blow molding machine

A blow molding machine makes hollow plastic parts such as bottles and tanks by inflating hot plastic inside a mold. Extrusion blow molding drops a tube of plastic, called a parison, into the mold; injection stretch blow molding first molds a preform, then stretches and blows it. See used blow molding machines and the blow molder buying guide.

Granulator

A granulator grinds sprues, runners, rejected parts and scrap plastic into regrind that can go back into the process. Rotor knives cut against bed knives, and the hole size of the screen sets the size of the regrind. Check the throat opening, knife condition and motor horsepower against what you grind. See used granulators and the granulator buying guide.

Process chiller

A process chiller pumps cooled water, or a water and glycol mix, through molds, extruder barrels, hydraulic systems or spindles to carry heat away and hold a steady temperature. Its capacity is stated in tons of cooling. On a used chiller, check the compressor, the refrigerant it uses, the pump, and whether it is air-cooled or water-cooled. See used chillers and the chiller buying guide.

Inspecting a used machine

Under-power inspection

An under-power inspection means seeing a machine connected to power and running: axes moving, spindle turning, tool changer cycling and the control showing its alarm history and timers. It shows faults a machine that is switched off hides. Machines KD Machinery has for sale can be seen under power, and KD encourages buyers to inspect in person or through a qualified third party.

Spindle hours

Spindle hours are the hours a machine’s spindle has actually turned. They measure wear better than age or power-on hours, which count every hour the control was switched on, cutting or not. Many CNC controls keep a spindle or cutting-time timer, but where it sits differs by control, and a control replacement or memory reset can zero it. Ask for a photo of both timer screens.

Ballbar test

A ballbar test checks a CNC machine’s accuracy by having it move in a circle around a fixed point while a telescoping bar records any deviation. The plot reveals backlash, squareness errors and mismatched axis servos in a few minutes. A recent ballbar printout is useful evidence when buying a used machining center.

Spindle runout

Spindle runout is how far the spindle taper wobbles off true as it turns, read with a dial test indicator on the taper or a precision test bar and given as total indicated runout (TIR). High runout shortens tool life and spoils finish and hole size, and it can point to worn spindle bearings.

Backlash

Backlash is lost motion when an axis reverses direction, caused by wear or play in the ball screw, its nut or the drive. It is checked with an indicator by moving an axis a small distance one way and back. A CNC control can compensate for small, steady backlash; large or uneven readings point to mechanical wear.

Hydraulic system check

A hydraulic system check looks at the pump, valves, cylinders, hoses and oil of a hydraulic machine, such as a press brake or an injection molding machine, while it runs. Watch for leaks, a noisy pump, pressure that builds slowly or drops under load, and oil that is dark, milky or running hot. Ask when the oil and filters were last changed.

Buying and selling with a dealer

Used machinery dealer

A used machinery dealer buys pre-owned industrial machines and resells them through its own listings, and often sells machines for other owners as well. The price comes from the asking price and negotiation, not from bidding. KD Machinery is an American used industrial machinery dealer based in Scottsdale, Arizona. Read more about KD Machinery.

Outright purchase

An outright purchase is a sale in which the dealer itself buys your machine, or your whole shop, at an agreed price. There is no auction and no wait for an end buyer. KD Machinery buys single machines and whole shops outright: one buyer, one offer. Start at sell your machines.

Shop buyout

A shop buyout is an outright purchase of the machines in a whole machine shop or plant, often when an owner retires, closes, consolidates or moves. One buyer makes one offer for everything, so the owner does not have to sell machine by machine. KD Machinery buys whole shops and plants outright. To start, see selling a whole shop or plant.

Brokered sale

In a brokered sale the dealer acts as the owner’s agent: it markets the machine, finds a buyer and arranges the sale, and the machine usually stays at the owner’s site until it ships. KD Machinery sells machines for other owners by brokerage through its own listings: there is no fee to list, and KD is paid only when the machine sells. Its conditions of sale apply the same as-is, where-is terms whether KD owns the machine or brokers it.

Dealer consignment

In a dealer consignment the owner hands a machine to a dealer to sell on the owner’s behalf, keeps title until it sells, and is paid from the sale, usually less an agreed commission. Where a broker mainly finds the buyer, a consignment puts the dealer in charge of the machine and its sale. KD Machinery takes consignments through its own listings on the same terms as a brokered sale. Consigning a machine to an auction is a different arrangement, which KD Auctions handles.

Free evaluation

A free evaluation is a no-charge estimate of what a used machine is likely to sell for, given to an owner who is thinking of selling. It is not a formal appraisal; KD Auctions prepares those for a lender, court, trustee, tax or insurance purpose. Ask KD Machinery for one through sell your machines.

As-is, where-is

As-is, where-is means the buyer takes the machine in its present condition, with any faults known or unknown, and collects it from where it sits. No warranty applies unless one is written on the invoice. KD Machinery sells every machine on these terms under its conditions of sale, which is why it strongly recommends inspecting first.

Limited startup warranty

A limited startup warranty is short cover on a used machine’s main components after it arrives. At KD Machinery it applies only when written on the invoice and when a KD Machinery-approved technician starts the machine within 10 calendar days of arrival; problems must be reported in writing in that period. It covers the spindle, ball screw, control, motors, drives and tool changer.

Wire transfer verification

Wire transfer verification means phoning the seller on a number you already trust to confirm its bank details before you send a wire. Criminals send forged invoices and emails with changed account numbers. KD Machinery’s conditions of sale require buyers to confirm its bank details by phone first. Call the main number, 480-922-1674.

Equipment financing

Equipment financing spreads the cost of a machine over monthly payments through a lender, usually with the machine as collateral. Financing is available on KD Machinery purchases, subject to credit approval. See financing.

Price terms

Asking price

The asking price is the price a seller publishes on a listing. It is a starting point for negotiation, not proof of what a machine is worth, and a machine can sell below it. When you research value, keep asking prices apart from realized prices.

Realized price

A realized price is what a buyer actually paid for a machine that sold, as opposed to what it was listed for. KD Machinery’s price guide is built from its own completed, paid sales, so it shows what machines actually brought; it is not a market-wide index.

Median price

The median is the middle sale price when a set of sales is put in order: half sold for more and half for less. It is used instead of an average because one unusually cheap or heavily optioned machine can pull an average a long way. KD Machinery’s rule for its price guide is to show a median only when a figure rests on at least 8 sales.

Middle 50%

The middle 50% is the price band holding the middle half of the sales, from the 25th to the 75th percentile, leaving out the lowest and highest quarters. It shows how widely typical prices run for a model. KD Machinery’s rule is to give it beside the median only at 8 sales or more, a plain range at 3 to 7 sales, and no figure below 3.

Sales count (n)

The sales count, often written n, is how many machines a price figure is based on. A median from many sales tells you more than one from a few. KD Machinery’s price guide states, for every figure, how many sales stand behind it.

Comparable sales

Comparable sales, or comps, are recent sales of the same make and model, or a close match, in similar condition and with similar options. They are the most direct evidence of what a used machine will bring. Adjust for year, hours, control, tooling and options before you compare.

Moving a machine

Rigging

Rigging is the skilled work of disconnecting, lifting, skidding and loading a heavy machine, and setting it in place at its new site. When you buy from KD Machinery, you arrange and pay for rigging and freight; KD can refer rigging and freight trades. Have the machine’s weight and footprint ready before you book a rigger.

Machine prep for shipping

Machine prep is the work done before a machine travels: draining coolant and fluids where needed, locking the axes, head and doors, protecting the control and way covers, and crating loose parts. KD Machinery can refer prep trades. Its guide to preparing and shipping a CNC machine walks through the steps.

Bill of lading

A bill of lading is the carrier’s shipping document: a receipt for the machine, the contract of carriage and a record of its condition at pickup. Note any visible damage on it before you sign at delivery. Under KD Machinery’s conditions of sale, the buyer completes the bills of lading and arranges transit insurance.

Auction and valuation terms

Terms such as buyer’s premium, hammer price, reserve price, fair market value and orderly liquidation value belong to auctions and formal appraisals. KD Machinery’s auction subsidiary, KD Auctions, defines them in its industrial auction glossary.