Falcon D251-626 Double thumbturn Deadbolt, Satin Chrome Finish

The Falcon D251-626 is a double thumbturn deadbolt from the D200 medium duty series in 626 satin chrome finish. It has a thumbturn on both the exterior and interior faces and no cylinder on either side. The bolt is thrown or retracted by thumbturn from either side and automatically deadlocks when fully thrown. No key, no key override. Rated ANSI/BHMA A156.5 Grade 2, ADA compliant, and Buy American Act (BAA) compliant. Backset adjusts from 2-3/8" to 2-3/4" with a lock-in-place helix mechanism that secures the backset setting after adjustment.

What a double thumbturn deadbolt is and where it belongs

A double thumbturn deadbolt, also called a non-keyed double deadbolt or double-sided thumbturn deadbolt, gives both sides of the door independent deadbolt control without requiring a key from either side. The most common applications are storm shelter doors and safe rooms, where occupants need reliable deadbolt security but a key cannot be part of the emergency operation sequence. Reaching for a key during a shelter event introduces a failure point that a thumbturn eliminates entirely.

Other specifications include interior security rooms where two-way access is needed without key management, connected suites or hotel rooms sharing a communicating door, and residential shelter-in-place applications. The D251 is also specified on secondary access points inside facilities where a deadbolt provides the right level of security but key control over that specific door isn't required. Because there's no cylinder on either side, there's nothing to pick, no keyway to compromise, and no key to lose.

Bolt construction and forced-entry resistance features

The 1" bolt on the D251 is cast zinc with a hardened steel anti-saw pin insert and a 1/4" thick hardened steel saw-resistant roller housed within the bolt. The saw-resistant roller spins when a cutting tool contacts the bolt face, preventing a saw from getting traction. The anti-saw pin insert adds a second layer of resistance. An integrated security shield protects the bolt from ice-pick attacks through the door face, which is a relevant threat on hollow core doors where a sharp instrument can be driven through the door material to manually retract a bolt.

The trim ring is 1" wrought brass or bronze reinforced with a steel security insert, free-spinning and tapered to resist wrenching and prying attacks on the visible exterior trim. Attachment uses 1/4" heat-treated steel through-bolts that thread directly into the back of the lock body. A metal dustbox reinforcer with three 3" screws ships standard for wood frame installations, addressing kick-in attacks at the strike plate by anchoring into the framing stud behind the door jamb.

Backset adjustment, fire rating, and door prep

The lock-in-place helix backset design allows the D251 to adjust between 2-3/8" and 2-3/4" and then lock the setting in place after adjustment, preventing backset drift during installation. The 1-1/8" x 2-1/4" square corner faceplate and 1-1/8" x 2-3/4" lipless square corner strike ship standard. Optional strike configurations including ANSI, T-strike, full lip, round corner, and security strike are available. Door thickness range is 1-3/8" to 1-7/8" standard, extending to 2-1/4" with a conventional cylinder housing adapter. For UL 10C 3-hour fire rated use as an auxiliary lock, specific listed configurations are available, identified by the Letter F and UL symbol stamped on the latch front.

For the complete range of Falcon D200 Grade 2 deadbolt configurations including single cylinder, double cylinder, and specialty functions, browse the Falcon Grade 2 D200 Series. The full selection of cylindrical deadbolts across all brands is available for comparison, and the broader deadbolts catalog covers single cylinder, double cylinder, and specialty configurations from multiple manufacturers.

The D251-626 is satin chrome finish. Confirm your door thickness and intended use before ordering. For applications requiring key access from either side, a different D200 Series model is the correct specification.