Dormakaba Simplex 5031BWL-26D Pushbutton Lock Satin Chrome for Best IC Core

The Dormakaba Simplex 5031BWL is the interior-combination-change variant of the Simplex 5000 Series mechanical pushbutton lock, paired with Winston Lever trim and prepped for a Best, Arrow, or Falcon small format interchangeable core. Extra heavy-duty construction with cast stainless steel internal drive components, direct-drive clutch-free design, and DOD-required interior combination change (combo is reset from inside the door, not outside). Combination entry plus mechanical key override via the IC core you install. 3-hour UL/ULC fire rated on A-label doors. 

What Is the Dormakaba Simplex 5031BWL Pushbutton Lock

Simplex (owned by Dormakaba since the 2015 Kaba-Dorma merger, previously sold under the Kaba Simplex, Unican, and Ilco brand names) is the original inventor of the mechanical pushbutton lock category. The 5000 Series is their flagship extra heavy-duty line, sitting above the lighter-duty 1000/L1000 Series in terms of specification and durability. Within the 5000 Series, the "5031" specifically indicates the interior combination change function with combination entry and key override. The "B" prefix in 5031BWL means it's prepped for Best-compatible small format interchangeable cores (also accepts Arrow and Falcon SFIC), and "WL" is the Winston Lever trim. No batteries, no wiring, no network connection. Fully mechanical, 100% standalone.

Simplex 5031BWL Specifications

Full specs for the door schedule:

• Function: combination entry plus mechanical key override

• Series: Simplex 5000 Series extra heavy-duty mechanical pushbutton lock

• Model variant: 5031 (interior combination change, DOD compliant)

• Trim: WL Winston Lever

• IC core prep: Best-compatible SFIC (also accepts Arrow and Falcon small format IC cores)

• Construction: extra heavy-duty cylindrical lock, solid cast housing, solid cast zinc levers, stainless steel cylindrical drive components

• Internal mechanism: clutch-free direct drive design with cast stainless steel drive parts

• Pushbuttons: 5 numeric buttons plus Enter button, vandal resistant, anodized aluminum, mechanical

• Combination code: 1 to 5 numbers per code, pressed individually or simultaneously, thousands of possible combinations

• Code change: lever release combination change tool, interior operation (DOD required)

• Emergency access: mechanical key override via installed IC core

• Handing: non-handed, field reversible in seconds

• Door thickness: 1-3/4" standard

• Backset: 2-3/4" (70mm)

• Latch: 1/2" throw standard with floating face plate, 3/4" throw optional with beveled faceplate

• Fire rating: 3-hour UL/ULC on A-label doors

• Power: fully mechanical (no batteries, no wiring)

• Audit trail: none (no electronics)

• Finish: 26D Satin Chrome (BHMA 626)

• Warranty: 3 years

Model Number Breakdown and DOD Interior Combo Change

The Simplex 5000 Series model numbers follow a strict convention. First two digits are the series (50), the third digit indicates the function: 2 = exterior combination change (combo reset from outside), 3 = interior combination change (combo reset from inside), 4 = exterior change plus passage mode, 5 = interior change plus passage mode. The fourth digit stays 1 across the family. So 5031 specifically means interior combination change with key override, no passage. This matters for federal government and Department of Defense specifications for SCIFs, classified research areas, and secure government offices where a door with exterior combination change is specifically disallowed because it could be tampered with from the unsecured side. The 5031 and 5051 are the two models in the family that meet DOD interior-change-only requirements.

Simplex 5000 Series Variants (5021 vs 5031 vs 5041 vs 5051)

The 5000 Series ships in four function configurations under the same chassis:

• 5021 = Exterior combination change, combination entry + key override (standard commercial use, easier field combo changes)

• 5031 = Interior combination change, combination entry + key override (this product, DOD compliant, no exterior tampering)

• 5041 = Exterior combination change, combination entry + key override + passage mode (adds a thumbturn/key to let the lock run free during business hours)

• 5051 = Interior combination change, combination entry + key override + passage mode (DOD compliant plus passage, used in federal offices with variable-hours access)

IC core prep options are consistent across the family: the "B" prefix indicates Best-compatible (like this product), "C" indicates Corbin Russwin, "M" indicates Medeco, "X" indicates Kaba/Dormakaba native keyway, "S" indicates Schlage. Finish codes on the 5031BWL specifically are: 26D Satin Chrome (this product), 55 Duranodic, 03 Bright Brass, 04 Satin Brass, 676 Black with Satin Chrome Accents, 744 Dark Bronze with Brass Accents.

How to Change the Combination on the 5031

Because the 5031 is the interior combination change variant, resetting the combination requires access to the inside of the door and the lever release combination change tool that ships with the lock. Full step-by-step combination change instructions are in the Simplex 5000 Series technical manual (available on the Dormakaba support site and linked in the product page resources section). If you've lost the change tool, replacement tools are available through our Simplex Accessories page. The 5031 is not end-user field-changeable without the tool, which is intentional for DOD and high-security environments.

Where to Buy the Dormakaba Simplex 5031BWL

We've stocked Dormakaba Simplex mechanical pushbutton locks since 2001, and the 5031BWL ships same day from the full Simplex 5000 Series Lever Lock lineup, specifically within the 5031 Interior Combination Change sub-category. To complete the installation with a Best SFIC core, pair with a core from our Best IC Core category so your locksmith can key it to your existing master key system. For broader evaluation across all mechanical pushbutton options, see the Mechanical Pushbutton Locks category.