Our take
The OKI B431dn is a monochrome LED printer for a wired workgroup. The manufacturer-authored U.S. specification sheet maps 91659903 to the black 120 V dn model and lists up to 40 ppm, automatic duplex, Ethernet, USB and parallel. It has a 250-sheet tray plus a 100-sheet multipurpose feed for 350 sheets standard. OKI's document gives an 80,000-page maximum monthly duty cycle, but not a recommended routine range. That distinction matters when deciding whether the printer fits a real workload.
A wired mono workgroup that values automatic duplex, Ethernet and a separate toner-and-drum consumables arrangement..
Skip it if you need copy, scan, fax, built-in Wi-Fi or a verified recommended monthly range; the used unit's exact part and condition should be checked.
Pros & cons
What could work for you, and what to consider before buying.
What works in its favor
- The 91659903 ordering code is identified as the black 120 V B431dn in the U.S. specification table.
- Automatic duplex and 350 sheets of standard input support routine shared printing.
- Separate toner and image drum provide distinct consumable components, and Ethernet is standard on the dn model.
What to weigh up
- The source does not provide a recommended monthly volume; 80,000 pages is a maximum duty-cycle ceiling.
- The exact model is print-only and does not provide copy, scan or fax functions.
- Built-in Wi-Fi is not documented; this configuration uses wired connections.
The key details
| Model covered | B431dn (91659903, Black 120 V) |
|---|---|
| Main functions | Monochrome LED print-only printer |
| Print output | Up to 40 ppm; 350-sheet standard input; recommended monthly range not documented |
| Two-sided printing | Automatic duplex; Ethernet, USB and parallel; no built-in wireless documented |
Performance figures are manufacturer claims. Source checked October 9, 2026. Regional models and included accessories can differ.
What the features mean for you
Match the exact part and voltage
The OKI-authored ordering table distinguishes the B431dn black 120 V part 91659903 from its tan 220 V counterpart. That is the relevant identity evidence for a U.S.-suitable configuration. Keep the part number with the model name when comparing listings, and inspect the label on a real unit. The B431d and B411dn are nearby models with different connection or paper details, so their specifications should not be borrowed to fill gaps in the dn profile.
Let automatic duplex reduce page handling
The B431dn has standard automatic two-sided printing. The printer turns paper between sides, which can make recurring reports easier to produce than a manual refeed workflow. OKI rates this model up to 40 ppm, but that is a manufacturer figure under test conditions rather than an observed result for every file. Paper size, weight, driver settings and a used machine's condition still affect whether a job prints as expected.
Plan around its paper and network setup
The base input is 350 sheets: a 250-sheet main tray and a 100-sheet multipurpose tray. OKI lists USB and parallel across the series and an OkiLAN Ethernet print server on the dn models. An optional 530-sheet second tray can expand capacity if it is actually installed. Wi-Fi is not documented as standard for the B431dn. For a shared queue, confirm the Ethernet port, driver path and installed trays on the exact unit.
Separate the toner and drum maintenance parts
OKI describes a two-piece consumables setup with separate toner and image drum. That means a buyer assessing a used printer should check both components rather than treating a fresh toner cartridge as proof that all imaging parts are new. The source lists nominal supply lives, but actual remaining life depends on prior use and the physical condition of the device. Ask what is included and review a print sample; manufacturer yields do not guarantee the state of an individual listing.
Use the duty cycle carefully
The OKI sheet states a maximum duty cycle up to 80,000 pages per month and does not give a recommended monthly range. That ceiling is a durability comparison, not a target for routine use. The matching profile therefore leaves both recommended-volume endpoints unknown. If workload sizing matters, seek an exact recommendation rather than treating the maximum as a comfortable monthly amount. A 350-sheet tray and 40 ppm rating can inform job setup but cannot replace a recommended-volume specification.
What else to compare
The Samsung SL-M3320ND is another wired mono duplex printer with Ethernet, though its saved packet also lacks a recommended monthly range. The HP M609x provides a documented enterprise range but is much larger-scale.
Before you buy
Does the B431dn include automatic duplex?
Yes. OKI's B400-series specification lists standard duplex printing for the B431dn.
Which interfaces are standard?
The U.S. sheet lists USB and parallel for the series and an internal Ethernet print server for the B431dn model.
Is 80,000 pages a recommended monthly target?
No. OKI calls it a maximum duty-cycle rating; the reviewed document does not state a 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.
- Manufacturer-authored OKI U.S. B400-series specifications hosted by a third party ↗ — checked October 9, 2026.
- OKI-authored B400-series U.S. specifications: 91659903 identity, speed, duplex, ports, trays and duty cycle ↗ — checked October 9, 2026.
The decision
The B431dn fits a wired mono queue that uses standard duplex and a larger input path. Keep its missing recommended volume, lack of wireless and exact 120 V part visible in the choice.
Is it the right fit?
Check the exact model and today’s offers on Amazon.