CNC Family Breakdown

Doosan DNM: The Number Is the Table Width, and It Tells You Nothing Else

The good news first. Unlike most machine families we break down, the DNM's number actually decodes cleanly, and you can check it in thirty seconds.

The bad news is what happens after that. Two machines badged DNM 5700, same year, same ISO 40 taper, same thirty pockets, both advertised as eight thousand rpm, can make 286 Nm or 118 Nm of spindle torque. Same headline speed. Two and a half times the cutting torque. And no listing we read distinguishes them.

That is the shape of this family. The model number is honest and useful for about one sentence, and then everything that decides what you are buying moves to the option list, the spindle architecture and the build sheet.

This breakdown covers both numbering schemes, the three traps that catch buyers hardest, the specs that get worse as the machines get newer, and what to check on a used one.

The number is the table width, and it is also the Y travel

Four for four, from Doosan's own brochures and product pages.

It is not X travel and it is not table length. A DNM 5700 has 1,050 mm of X and a 1,300 mm table. If you read the number as anything other than table width, you will get the machine wrong.

The three-digit machines track the same axis and round it down to a marketing figure. A DNM 400 has a 435 mm table. A DNM 500 has 540. A DNM 650 has 670. A DNM 750 has 760. So the old number understates the machine and the new one states it exactly, which is the cleanest way to hold the two schemes in your head at once.

One exception that catches people. The 5-axis machines use a third logic entirely. The DNM 200/5AX and DNM 350/5AX are named for their rotary table diameter, 200 mm and 350 mm. They also sit under 5-axis machining on the manufacturer's site rather than under the DNM vertical machining centers, and they share almost nothing with a DNM 5700 beyond the taper and the badge.

As for what the letters DNM stand for, nobody knows. We checked ten brochures, manuals, product pages, press releases and the corporate history page and found no published expansion anywhere. What is unusual here is that we could not find a dealer expansion either. On most families the internet is full of confident wrong answers. On this one it is silent.

The DNM 4000 is not the DNM 400's replacement, and it is not close

This trap is nearly unavoidable, because the numbering builds it in. One digit apart, and they surface in the same searches.

The DNM 4000 is a compact machine announced in April 2018 for lean cells. It is barely half the machine a DNM 400 is, and it carries 200 kg less on the table. The DNM 400's actual successor is the DNM 4500.

Worth knowing what the little machine is good at, though, because it is the one genuinely surprising thing in this family: the DNM 4000 rapids at 48 m/min on all three axes, faster than any 4500, 5700 or 6700 in any generation.

The renaming was not a rename, and it was only partial

The third generation arrived in June 2016 and moved the mainstream models from three digits to four. Doosan announced it with a claim of six percent more cutting space, fourteen percent bigger tables and twenty-five percent heavier load capacity.

Run the arithmetic on the three replacement pairs and the claim holds unevenly. The table figure lands on all three. The load figure lands on one of the three. And the cutting-space figure matches none of them, working out at roughly nine, nine and two percent.

Three things fall out of that table that matter to anyone cross-shopping the two schemes.

Z travel never changed on any pair. Anyone telling you a four-digit machine gives more Z than its three-digit predecessor is wrong.

The 4500 brought zero extra table load over the 400 II. The generational load claim holds for the 5700 and 6700 and not for the small machine.

A DNM 650 II and a DNM 6700 have identical Y and Z travel and the same taper. The 6700 gives you 30 mm more X, a 200 mm longer table and 300 kg more load. If your work is nowhere near those limits, they are functionally the same machine, and the 650 II should be priced like it.

Three digits does not mean old

The renaming was only partial, and this is the part almost nobody accounts for. The ISO 50 taper machines, the DNM 500/50 II and 650/50 II, and the entire DNM 750 II line kept their three-digit names right through the switch and into 2018 and beyond. We found 2016 and 2018 build DNM 750 IIs in current listings. So a three-digit DNM is not automatically an older machine, and dating one by its numbering scheme will cost you.

The four-digit spec ladder

Figures from the fourth-generation catalogue, publication code EN 250321 SU, dated 21 March 2025.

The L variants extend X on the same Y and Z: the 4500L to 910 mm, the 5700L to 1,300, the 6700L to 1,500. Above them sits the 6700XL at 2,100 mm of X on a 2,200 mm table, which is 82 inches of X in a machine that competes on price with 40 inch machines from other brands. If you fixture five or six parts in a row, or machine long weldments, the XL is the argument for this whole family and there is very little else at the money.

One figure we are flagging rather than smoothing over: the DNM 6700's mass reads 8,500 kg in the 2016 and 2025 catalogues and 8,000 kg in the 2020 one. Same machine, three manufacturer documents, two numbers. Use 8,500 and know why they disagree.

The three-digit machines that are still three-digit

The ISO 50 pair is the underrated corner of this family. Three times the torque of the 40 taper machines, on roller LM guides, at a price that reflects the Doosan badge rather than the taper. What you pay for it is cycle time: 2.5 seconds tool to tool against 1.2, and 24 pockets against 30.

One caution on those spindle figures. The May 2015 new-products catalogue quotes the ISO 50 spindle at 15/11 kW and 286.4 Nm; the 2017 brochure quotes 22/11 kW and 353.2 Nm. Both are manufacturer documents. Either the rating was uprated between them or one is an option, and we could not establish which.

Five specs that go the wrong way

1. The fourth-generation 6700 never got the rapids upgrade. The 4500 and 5700 went from 36/36/30 to 42/42/36 m/min in 2023. The 6700 and 6700L stayed at 36/36/30. A 2024 DNM 6700 rapids no faster than a 2017 one.

2. Chip to chip time got worse in the fourth generation. Third generation: 3.2 seconds across all three models, the 6700 included. Fourth generation: 4.1 seconds, and 4.4 on the 6700, because the ATC shutter that used to be optional is now standard. You get 3.2 back only by deleting the shutter. The October 2023 launch release states that tool change speeds are faster than the third generation. The catalogue that accompanied it prints otherwise. Both are manufacturer documents and they do not reconcile.

3. The 6700XL is the slowest machine in the four-digit line. Thirty metres a minute on all three axes against 36/36/30 for every other third-generation model. The biggest machine has the slowest X and Y.

4. The DNM 750L II is slower than the DNM 750 II. 24/24/24 against 30/30/24. Buying the longer bed costs you twenty percent of your X and Y rapid.

5. The 4500 has a lower continuous spindle rating than its bigger siblings. 18.5/11 kW against 18.5/15. Same peak headline, different continuous duty, and continuous duty is what a long steel cycle actually uses.

Two machines badged DNM 5700 can be 168 Nm apart

Here is the option that costs the most and gets described the least.

The standard eight thousand rpm spindle makes 117.8 Nm. There is also an optional eight thousand rpm high-torque spindle that makes 286 Nm. Same headline speed. Same taper. Two and a half times the torque, and a difference of 168 Nm between two machines that a listing will describe identically as an 8K DNM 5700. Worth knowing the trade: the high-torque spindle is rated 15/11 kW against the standard machine's 18.5/11, so you are buying torque with rated power.

That is one line item. Here is the rest of what varies on machines that look the same in an advert:

Through-spindle coolant, at three pressures or absent. 2 MPa, roughly 290 psi. 3 MPa, roughly 435 psi. 7 MPa, roughly 1,015 psi. The 2 MPa tier comes in 1.5 kW and 4 kW versions, so the option list reads as four line items across three pressures. The 2016 catalogue offered only 2 and 7 MPa; the middle tier appears later. This is the most under-described option in used listings, because sellers write TSC and stop.

Flood coolant, also tiered. The third-generation catalogue puts standard flood at 0.15 MPa, about 21.8 psi, with an option at 0.7 MPa. The fourth-generation catalogue prints no standard pressure at all and lists 0.16, 0.45 and 1 MPa, so its lowest entry is effectively the base rather than an upgrade. A DNM sold as ready for stainless on base flood is not ready for stainless.

Probing, or the wiring for it. A distributor states that fourth-generation machines include Renishaw probe preparation with the probe itself optional. That is distributor copy: the manufacturer's own catalogue lists Renishaw probes under optional equipment and does not show the preparation as standard. Either way, probe ready and probe equipped are two different listings, and we read one for a 2016 DNM 5700 that had the receiver and no probe.

Fourth axis, or the harness for it. Adding a real rotary means the table, a matched amplifier, cables, mounting, grounding, parameter work and a dealer-side option unlock. Four-axis wired is not four-axis capable, and the gap between them is a four to five figure project.

Linear scales. Optional in every generation. Never standard. Do not assume sub-ten-micron capability without either scales or a ballbar plot.

A raised column, at 150, 200 or 300 mm. Rare, and it changes the Z envelope, so a machine with one does not match the standard spec sheet you are comparing against.

Look-ahead. AI Contour Control I and II, at 40, 200, 400, 600 or 1,000 blocks, is optional rather than standard. A mold shop buying a used DNM for three-dimensional surfacing should verify the block count rather than assume it.

It is not a Mynx, and the travels will not tell you apart

This confusion is documented in the wild. A live listing we found is titled with both product lines in one string, and its specifications describe a Mynx.

The reason it happens is that the travels are identical. Mynx 6500 is 1270 by 670 by 625. DNM 650 is 1270 by 670 by 625. Mynx 5400 is 1020 by 540 by 530; DNM 500 is 1020 by 540 by 510. You cannot separate them on the envelope.

You can separate them by looking at the guides. The DNM uses roller-type LM guides on all axes as a standard feature, with grease lubrication on all axes. The Mynx uses a box guideway structure, which the manufacturer describes as suited to heavy cutting. Different rigidity, different damping, different wear behaviour, different maintenance and different resale.

So: roller LM blocks with grease fittings means DNM. Scraped or turcite box ways means Mynx, whatever the badge on the sheet metal says. There is no DNM 6500 in the DNM catalogue at all.

Related traps in the same searches: DMV, MV and VM are the older Daewoo-era vertical lines, and a 2005 DMV is not an old DNM. VC and DVF are separate 5-axis lines. And the grease lubrication point has a live contradiction attached: one third-party maintenance guide claims DNM machines consume 0.2 to 0.4 litres of way oil per eight hour shift, which cannot be true of a grease-lubricated machine. Either that guide is wrong or earlier DNMs used central oil lube. We could not establish which, so resolve it by looking at the machine rather than the paperwork.

Three spindle architectures, three different repair bills

This is the most useful inspection finding on the family, and it comes from published teardowns rather than marketing.

Three-digit machines: belt driven, grease packed. A DNM 400 spindle is documented as grease lubricated and belt driven, capable of 12,000 rpm. Cheaper to rebuild than the alternatives, but the belt and the grease-life clock are real and they are on a schedule nobody tells the second owner about.

Four-digit machines: direct coupled. The manufacturer states that direct-coupled spindles are standard on the four-digit line, to cut vibration and noise. Fourth-generation 5700s add oil-jacket spindle cooling.

S and HS machines: integral motor, air-oil lubricated. A DNM 500HS spindle is documented as air-oil lubricated, motor driven, 15,000 rpm, on a Big Plus 40 taper. Rebuilds cost materially more, and the air-oil supply is itself a live failure point. Verify the air-oil unit runs, that the air is dry, and that the lubricator reservoir has been maintained.

Both published teardowns found damage beyond the bearings. The DNM 400 came in seized, and the finding was catastrophic failure of the number two bearing, whose cage had been destroyed and had contaminated the number one bearing. Along the way the retention nut was galled badly enough that removing it took extreme heat and torque and bent the drawbar in the process, and the taper was in poor visible condition with swirl marks, needing grinding, chrome plating and finish grinding. The DNM 500HS, presented by its owner as simply noisy, turned out to have a worn rear roller bearing, high taper runout, worn grippers, and Bellevilles that had worn a significant amount of material off the drawbar.

Two things follow. Scope the taper, because buildup and swirl marks mean a prior crash and that is a chrome-and-regrind job rather than a wipe-down. And pull a drawbar force reading, because on both machines the drawbar assembly had taken damage that the presenting complaint gave no hint of.

One more thing to read off the spindle nose: whether the taper is Big Plus or standard. Big Plus turns up on the DNM 4000, on the DNM 5700S as far back as 2018, and on the fourth-generation 5700. A buyer with a standard-taper tool crib who buys a Big Plus machine gets none of the benefit and usually does not know it.

The ballnut failure documented on this family

A ballscrew rebuild specialist publishes a DNM 500 II case with a specific chain of events, and it is worth knowing because the leading indicator is free to check.

The symptom the owner reported was a horrible cement mixer noise in rapid traverse. The cause was a lubrication line to the ball nut that had been pinched, bent or broken, starving the nut. The progression runs noise at high rapids, then positioning error and lost motion, then in the worst case seizure. Specific to this family, the DNM 500 II used PMI ballscrews with an unusual plastic bearing-circulation insert that the rebuilder describes as uncommon.

So on inspection: rapid every axis end to end and listen. A grinding or rumbling sound in rapid arrives before measurable backlash does. Then trace the lube lines to each ball nut and look for pinch points, kinks and breaks. That is a two minute check that almost nobody performs, and it is the difference between buying a machine and buying a ballscrew job.

The tool changer, with alarm numbers

The DNM uses a double-arm, side-mount, random-access changer. Three things worth knowing before you inspect one.

Random tool assignment is normal and is not a fault. The double-arm changer does not keep tools in the same pot; it moves them each time. Buyers coming from a fixed-pot machine read this as a defect. Tool positions are readable in the control's tool data table, reachable through the Custom softkey menu on Fanuc-controlled units.

Arm misalignment is the named suspect. On a forum thread about a DNM 500 dropping tools before seating them, worse with heavy tools, another participant suggested the arm might be out of alignment and recommended checking it with a three-piece alignment tool described as expensive. We want to be precise about what that is and is not. Nobody attended the machine, nothing was corrected, and the thread ended with the owner sent to a dealer because he did not have the tool. Treat it as the first thing to check rather than as a diagnosis, and ask whether the seller's shop owns the tool or has access to one.

Two alarm numbers to search for in the history. Alarm 2274 and alarm 2252, reported together on a DNM 400 in a December 2014 thread where the arm stuck on a pot, one tool fell out of the magazine and another lodged in the arm. A Doosan maintenance manual index lists 2274 as a tool changer spindle and magazine side alarm and 2252 as an ATC initial position alarm. The owner in that thread called 2252 an interlock alarm, which is his paraphrase rather than the manual's wording. Alarm 2252 turns up again on a 2020 DNM 4500 thread, so it is not confined to one generation.

On inspection, run twenty or more consecutive tool changes with real, heavy tooling in the pockets. Not empty pots and not the same two tools. Watch for hesitation at the seat and for the gap between arm and flange. And confirm the machine's holders match its taper standard, since mixing CAT and BT holders in one machine is a straightforward way to cause the fault you are inspecting for.

Control generations, and where the real break is

Two things to take from that table.

The badged controls are Fanuc. Doosan Fanuc i and DN Solutions Fanuc i Plus are Doosan-badged Fanuc 0i-M class controls, not proprietary ones, so standard Fanuc posts work with minor tuning. We could not find the exact underlying Fanuc series number stated in any manufacturer document, so we are not going to assert one.

The sharpest break is networking, not machining. MTConnect, OPC UA and 2 GB of program memory appear as explicit catalogue options only from the fourth generation. A pre-2016 DNM II on an 0i-MD is realistically a drip-feed or USB machine. If your shop runs machine monitoring, that is a concrete reason to skip the older three-digit machines that has nothing to do with how they cut.

And note that Siemens and Heidenhain DNMs exist across the whole production run and are common in European used stock. They are not rebadged Fanucs, they need their own posts, and a Siemens 828D DNM is not cross-shoppable with a Fanuc one on programming infrastructure.

Why there is no price band in this article

Because the dispersion is the finding, and a band would hide it.

Two 2015 DNM 400 IIs were asking 44,500 dollars and 62,000 dollars on two platforms on the same day. That is a 39 percent spread on nominally the same machine and year. A 2017 DNM 5700 appeared at 79,500 dollars on two platforms, which is one machine counted twice rather than two data points.

Every figure in this article is an asking price. Not a market value, not an appraisal, not a transaction record. Several were still displayed after the machine was marked sold.

One aggregate figure is worth reporting because it says something about the family rather than about any machine: across 218 Doosan vertical machining centers from 54 sellers on a single platform, the average asking price was roughly 52,800 dollars with a range of 20,000 to 100,000. That is a narrow band with no four-figure floor, which is unusual. Doosan does not have the bottom end that Haas and Hurco have on the used market. If you are shopping the very cheap end of used VMCs, this family is not where you will find it.

And one correction to a thing we assumed going in. The DNM is not the highest-volume used VMC. On the platforms we counted, Haas outnumbers Doosan by roughly seven to one and Mazak by roughly two to one. What the DNM carries instead is a higher average asking price than Haas, Hurco or Okuma and the narrowest asking band of anything we measured. It is the mid-tier machine without a bargain basement.

Resell CNC Take

The DNM is the rare family where the model number is honest, decodes in one sentence, and then stops helping. Table width and Y travel, and that is everything the badge owes you. After that the machine you are buying is defined by the spindle architecture, the torque option, the coolant tier, whether the probe is in the drawer, whether the fourth axis is a table or a harness, and which of three control eras it was born into. That is good news for a buyer who inspects, because 39 percent asking dispersion on identical model years means the informed buyer wins real money on this family. It is bad news for anyone shopping from spec blocks, because the spec blocks are all the same. Get the build sheet, read the spindle nose, and rapid every axis with your ears open before you talk price.

Who it suits, and who it does not

It suits the job shop that has run out of table and torque on a 40 taper machine one class down. A DNM 5700 gives 41 by 22 inches with a 1,000 kg table load, and a 6700 gives 51 by 26 inches and 1,300 kg. That is genuinely more machine under the part. It suits steel and stainless work in the one to four hour cycle range, particularly the buyer who finds one of the 286 Nm high-torque units, which is the configuration most often overlooked in listings. It suits long-part and multi-fixture work, where the 6700XL's 2,100 mm of X has very little competition at the money. It suits shops with in-house Fanuc competence or an existing Fanuc fleet. And it suits anyone who wants a 50 taper at 40 taper money, which is what the DNM 500/50 II and 650/50 II are.

It does not suit small-part high-rpm aluminium production. The base machine is 8,000 rpm on low-pressure flood, and turning it into an aluminium machine takes the 15,000 rpm spindle plus through-spindle coolant plus high-pressure flood, three options that all had to be ordered new. It does not suit anyone who needs a rotary and has not budgeted for one, because four-axis wired is a harness and not a capability. It does not suit the one-machine shop with no service relationship and no Fanuc skills, since the failure clusters on this family, the ATC alignment, the chiller, the air-oil and the through-spindle coolant, all need a technician. And it does not suit micron-class work without verified scales and a ballbar plot.

What to demand before you wire funds

The build sheet or the machine's option list. On this family that single document is worth more than the entire advert, because it settles the torque option, the coolant tier, the probe, the fourth axis and the magazine size at once.

A photograph of the spindle nose. Big Plus or standard, and the taper standard the holders match.

Which spindle architecture it is. Belt driven on a three-digit machine, direct coupled on a four-digit one, integral motor air-oil on an S or HS. If it is air-oil, verify the unit runs, the air is dry and the reservoir has been maintained.

Drawbar force on a gauge, and the taper scoped. Both published teardowns on this family found drawbar-side damage alongside the bearing wear, and both needed taper regrinding.

Every axis rapided end to end while you listen. A cement-mixer rumble in rapid is the leading indicator of a starved ball nut, and it arrives before backlash is measurable.

The lube lines traced to each ball nut, looking for pinch points, kinks and breaks.

Twenty or more consecutive tool changes with heavy tooling loaded. Then the alarm history, searched for 2252 and 2274.

The guides, looked at directly. Roller LM blocks with grease fittings means DNM. Box ways means you are looking at a Mynx no matter what the listing says. And on a grease machine, check the pump or cartridge has actually been serviced, because the wrong maintenance here is oil and the failure is silent.

The spindle oil chiller run warm, confirmed cycling and holding, if the machine has one.

Through-spindle coolant tested at pressure, not at idle, and the actual pressure tier confirmed rather than the word TSC.

Frequently asked questions

What does DNM stand for on a Doosan?

Nothing the manufacturer has ever published. We checked ten brochures, product pages, a maintenance manual, press releases and the corporate history page, spanning 2015 to 2025, and none of them expands the letters. What makes this family unusual is that we could not find a dealer expansion either. On most machine families the internet is full of confident guesses; on the DNM it is simply silent. Anyone who tells you what it stands for is inventing it.

What does the number mean on a Doosan DNM?

On the four-digit machines it is the table width in millimetres with a zero added, and it is also exactly the Y travel. DNM 4000 has a 400 mm table and 400 mm of Y, the 4500 has 450 and 450, the 5700 has 570 and 570 and the 6700 has 670 and 670. It is not X travel and it is not table length. The older three-digit machines follow the same axis rounded down, so a DNM 650 has a 670 mm table and a DNM 750 has a 760 mm table. The 5-axis models use a third logic entirely, naming the rotary table diameter.

Is a Doosan DNM 500 the same machine as a DNM 5700?

No. The 5700 is the successor in the same size class, not a renamed 500. It adds 30 mm of X, 30 mm of Y, 100 mm of table length, 30 mm of table width and 200 kg of table load, going from 800 to 1,000 kg. Z travel is unchanged at 510 mm, which is true across all three replacement pairs. If a part fits a DNM 500 it will fit a 5700, but not the reverse at the edges. The renaming happened around 2015 and 2016 with the third generation.

Is the DNM 4000 a smaller version of the DNM 4500?

It is a much smaller machine and it is not the DNM 400's successor either, which is the trap the numbering creates. The DNM 4000 has 520 by 400 by 480 mm of travel, a 650 by 400 mm table, a 400 kg load limit, a 20-pocket magazine and a 3,300 kg mass. A DNM 400 is 762 by 435 by 510 on a 920 by 435 table at roughly 5,000 kg. The 400's actual replacement is the 4500. One redeeming oddity: the 4000 rapids at 48 m/min on all three axes, faster than any 4500, 5700 or 6700 in any generation.

What is the difference between a Doosan DNM and a Doosan Mynx?

The way construction, and you cannot tell from the travels. A Mynx 6500 is 1270 by 670 by 625 and so is a DNM 650. A Mynx 5400 is 1020 by 540 by 530 against the DNM 500's 1020 by 540 by 510. The difference is that the DNM runs roller-type LM guides on all axes with grease lubrication as standard, while the Mynx uses a box guideway structure the manufacturer describes as suited to heavy cutting. That means different rigidity, damping, wear behaviour, maintenance and resale. Look at the guides rather than the badge, and note there is no DNM 6500 in the DNM catalogue.

Does a Doosan DNM have box ways or linear guides?

Linear guides. Every DNM we could verify uses roller-type LM guides as a standard feature, including the ISO 50 taper machines and the compact DNM 4000, with grease lubrication on all axes rather than oil. That is the family's defining construction choice and the thing that separates it from the box-way Mynx line. One caution: a third-party maintenance guide claims DNM machines consume way oil per shift, which contradicts the grease specification. Either that guide is wrong or earlier machines used central oil lube, and we could not establish which, so check the machine itself.

What spindle does a used Doosan DNM have?

One of at least three architectures, and they fail and rebuild differently. Three-digit machines use a belt-driven, grease-packed spindle. Four-digit machines use a direct-coupled spindle as standard. S and HS machines use an integral-motor, air-oil lubricated spindle at 15,000 rpm, which costs materially more to rebuild and adds the air-oil supply as its own failure point. Separately, the standard 8,000 rpm spindle makes 117.8 Nm while an optional 8,000 rpm high-torque spindle makes 286 Nm, so two machines advertised identically as 8K can be 168 Nm apart.

Is a Doosan DNM still supported now that the company is DN Solutions?

The DNM name survived the rebrand unchanged and the family is still in production, with a fourth generation launched in October 2023 using the same model numbers. The corporate line runs Daewoo, then Doosan Infracore from April 2005, then Doosan Machine Tools from May 2016, then DN Solutions from May 2022. No DNM model was renumbered or dropped at the rebrand. The only visible change is the control badge, from Doosan Fanuc i to DN Solutions Fanuc i Plus. A machine built in 2022 can legitimately carry either badge, and the badge is not a specification difference.