Our take
Lexmark's MS431dn is a monochrome laser printer for an office that needs quick text output and automatic two-sided printing. Lexmark identifies U.S. part 29S0050, rates output up to 42 pages per minute on Letter, and recommends 800–8,000 pages per month. Integrated duplex is standard. Standard paper input is 350 sheets across a 250-sheet tray and a 100-sheet multipurpose feeder. Gigabit Ethernet and USB provide wired network and direct connection paths; built-in wireless is not included. This gives the MS431dn a clear office role without multifunction features. Teams that need scan, fax, Wi-Fi, or a larger tray reserve should compare another configuration.
A wired small-office or department queue needing fast monochrome duplex output and a published workload range up to 8,000 pages monthly..
Choose another product if you need color, scanning, fax, built-in Wi-Fi, or more paper capacity than the 350-sheet standard input.
Pros & cons
What could work for you, and what to consider before buying.
What works in its favor
- Lexmark documents up to 42 ppm Letter and integrated automatic duplex for routine two-sided office work.
- The 800–8,000 monthly recommendation helps compare intended workload without using maximum duty cycle as a target.
- Gigabit Ethernet, USB, and a 100-sheet multipurpose feeder support distinct wired and media workflows.
What to weigh up
- The MS431dn is print-only and cannot replace a copy, scan, or fax device.
- Lexmark lists no built-in wireless; remote placement requires an Ethernet path or a separate network solution.
- The standard input is 350 sheets, below enterprise printers configured with large or multiple drawers.
The key details
| Model covered | MS431dn |
|---|---|
| Main functions | Monochrome print only |
| Print output | Up to 42 ppm Letter; 800–8,000 recommended pages monthly |
| Two-sided printing | Automatic duplex; 350-sheet input; Gigabit Ethernet and USB |
Performance figures are manufacturer claims. Source checked October 11, 2026. Regional models and included accessories can differ.
What the features mean for you
Is monochrome print-only enough?
Lexmark identifies the MS431dn as a monochrome laser printer, not a multifunction unit. That focused design fits a team whose primary need is black text and who already has separate scanning and copying equipment. It avoids paying for feeder or fax features that won't be used. It cannot make color pages or capture originals, so an office with mixed documents should compare the full equipment setup rather than the printer alone. Confirm the exact 29S0050 part number because Lexmark uses suffixes to signal materially different features, including wireless and duplex.
Will 42 ppm and the recommendation suit your workload?
Lexmark rates the MS431dn up to 42 ppm on Letter and recommends 800–8,000 pages monthly. The rated speed is a maximum under specified conditions, not a measured result on every host or document. The monthly range describes recommended average use and is the relevant finder attribute; the separate maximum duty cycle is not a target. The range covers lighter departmental use through a robust workgroup level. If your needs are far below 800 pages, a less substantial model may make more sense; consistently heavier monthly totals warrant a higher-capacity device.
What does the duplex feature add?
Lexmark lists integrated duplex as standard and provides a separate duplex print-speed figure. That means the printer can turn sheets automatically for two-sided jobs instead of asking a user to reinsert them. This is practical for reports, handbooks, or recurring packets. It is not a scanner feature: there is no ADF or scan path on the MS431dn. Verify the duplex mechanism on an individual used unit, especially if the seller describes the printer broadly by its series name. The official model page gives the capability, while a physical check confirms the actual machine's condition.
Can the wired interfaces work for your room?
Lexmark lists Gigabit Ethernet and USB, and says wireless is not built in. Ethernet makes sense where the printer will join a wired office network; USB supports a directly connected host. If a printer must sit in a location without a network cable, the standard MS431dn does not supply the Wi-Fi route some personal models do. Plan cabling and permissions before choosing it. A network connection does not automatically handle scanning because this is not an MFP, and current host compatibility should be checked separately.
Is 350 sheets enough standard input?
The standard paper system includes a 250-sheet tray and 100-sheet multipurpose feeder, for 350 input sheets, with 150-sheet output. The multipurpose path accommodates occasional media changes without emptying the main tray. Optional trays can expand capacity, but those are not part of the standard profile and should not be assumed present. For a small office this may keep ordinary work moving; for a high-volume team it may mean more refills than a larger system. Check which trays are included with the offered 29S0050 unit and compare capacity with actual printing cadence.
What else to compare
For copy, scan, or fax, choose a mono MFP. For wireless placement, compare an exact model with built-in Wi-Fi; for a larger paper reserve, compare an enterprise printer with standard extra trays.
Before you buy
Does the MS431dn include automatic duplex?
Yes. Lexmark lists integrated duplex as standard on the MS431dn, so it turns pages automatically for two-sided print jobs.
Can it join Wi-Fi without an accessory?
No built-in wireless is listed for the MS431dn. Lexmark documents Gigabit Ethernet and USB as standard connections.
How many pages should it print monthly?
Lexmark recommends 800–8,000 pages monthly; its maximum duty-cycle figure is a separate ceiling, not the normal target.
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. MS431dn exact-model product specifications ↗ — checked October 11, 2026.
- Lexmark U.S. product page: exact part, speed, duplex, paper, ports, wireless status and recommended monthly range ↗ — checked October 11, 2026.
The decision
The MS431dn is a fast, duplex-capable wired mono printer with a broad monthly range. Print-only operation, absent Wi-Fi, and a 350-sheet tray define its fit.
Is it the right fit?
Check the exact model and today’s offers on Amazon.