Our take
The Lexmark CS431dw is a focused color printer for a team that wants automatic duplex and network sharing but does not need a built-in copier, scanner or fax. Lexmark's U.S. record maps part 40N9320 to this exact model, rates black and color output up to 26 pages per minute, and gives a 750–5,000 page recommended monthly range. Standard Ethernet, 802.11ac wireless and integrated duplex are useful in a small or medium shared office. Its standard paper tray is more modest than the workload range may suggest, so consider refill frequency and optional tray needs alongside the headline speed.
A small or medium workgroup needing networked color output and automatic two-sided printing without multifunction features..
Pass if you need copy, scan, fax or an ADF; the CS431dw is a print-only model and does not provide those functions.
Pros & cons
What could work for you, and what to consider before buying.
What works in its favor
- The U.S. part 40N9320 has automatic duplex, Wi-Fi and Ethernet documented as standard.
- A 750–5,000 page recommended monthly range covers a wider shared-office routine than a personal printer.
- Color and black print speeds are both rated up to 26 ppm on Letter paper.
What to weigh up
- The 250-sheet tray and one-sheet feed require replenishment for longer batches.
- Copying, scanning and faxing require separate equipment because this is print-only.
- Lexmark specifies region-matched replacement cartridges, so supply compatibility should be confirmed for the exact unit.
The key details
| Model covered | CS431dw (40N9320) |
|---|---|
| Main functions | Print only |
| Print output | Color laser; up to 26 ppm Letter |
| Two-sided printing | Integrated automatic duplex |
Performance figures are manufacturer claims. Source checked October 7, 2026. Regional models and included accessories can differ.
What the features mean for you
Print-only is the useful boundary
Lexmark describes the CS431dw as a color laser printer rather than a multifunction system. That makes the product easier to place in a shared output role when a separate scanner or office copier already handles incoming documents. The manufacturer rates both black and color Letter output up to 26 pages per minute, but a rated speed does not establish the time for a particular job or the condition of an older machine. If employees often need to digitize signed forms or make quick paper copies, choosing an MFP can remove a handoff. If those needs are handled elsewhere, this model avoids paying attention to unused capture functions.
Automatic duplex helps with recurring packets
The integrated duplex unit turns each sheet for automatic two-sided output. This saves a manual reloading step for handbooks, internal reports or class material, while keeping the job within the same printer queue as single-sided pages. Lexmark's product page specifies duplex speeds separately from one-sided output, so regular two-sided work should be planned around that distinction rather than assuming it runs at the same rate. Duplex printing does not imply a duplex scanner or copier; the CS431dw is print-only. For users who rarely print both sides, a less capable paper path may still be adequate, but this model makes repeated duplex jobs simpler.
Wi-Fi and Ethernet suit a shared placement
The standard ports list 802.11ac wireless, Gigabit Ethernet and USB. That gives an office a choice between a fixed wired installation and a wireless location, while USB remains available for a direct computer connection. The exact network route should fit the site's security policy and the computers that will print to it. A radio built into the model does not ensure that an old device is still configured or can join a changed network, so verify setup and firmware on a particular offer. Ethernet can be useful where a stable wired queue matters; Wi-Fi avoids requiring the printer to sit beside the network jack.
Monthly guidance and tray capacity describe different needs
Lexmark recommends 750 to 5,000 pages per month, while the standard input is 250 sheets plus a single-sheet manual feed and output capacity is 100 sheets. The recommendation speaks to the normal work range the maker associates with the printer; it does not remove the need to refill paper during a long run. Lexmark offers an optional 250-sheet tray, which can increase input capacity to 750 plus the bypass. Check whether that accessory is actually present before relying on it. A team with continuous batches may care as much about refill intervals and output stacking as the monthly recommendation.
Verify the exact regional printer and supplies
The candidate part clue 40N9320 matches Lexmark's U.S. CS431dw page. Lexmark notes that replacement cartridges are designed for particular regions, so confirm the supply region and model label on a used or renewed machine before ordering toner. The product listing cannot establish remaining cartridge yield, imaging-unit life, or the seller's warranty terms. Inspect the standard tray, feed rollers, wireless setup and Ethernet port if possible, and check driver support for the computers in the intended office. A model-specific search link can help find offers, but current price and inventory remain matters for the seller to confirm.
What else to compare
For integrated copy, scan and fax, compare the Lexmark CX331adwe; it adds those functions but has a lower 600–2,500 page recommendation and a simplex ADF.
Before you buy
Does the CS431dw include automatic duplex?
Yes. Lexmark lists integrated automatic duplex printing for the exact U.S. CS431dw part 40N9320.
Does the CS431dw copy, scan or fax?
No. Lexmark classifies it as a color printer; copy, scan and fax functions are not part of this model.
What monthly page range does Lexmark recommend?
Lexmark gives the CS431dw a 750 to 5,000 page recommended monthly range.
Where can I check the current price?
Use the Amazon link for current offers. Check the exact model, seller, product condition, delivery, and return terms. This page does not display a live price or confirm stock.
Sources & review basis
We use the following manufacturer documentation for the product features above. Our suitability notes and buying advice are editorial judgments based on those features, not measured performance results.
- Lexmark U.S. CS431dw product page and specifications ↗ — checked October 7, 2026.
- Lexmark U.S. CS431dw part 40N9320 product page, connectivity, print speed, duplex and workload ↗ — checked October 7, 2026.
The decision
Choose the CS431dw when a shared color queue needs automatic duplex and network access but does not need paper capture. The smaller standard tray and print-only role define its limits.
Is it the right fit?
Check the exact model and today’s offers on Amazon.