dormakaba HZ 43-FL Automatic Flush Bolt Left 22mm Concealed for Fire Doors

Product Overview

The dormakaba HZ 43-FL is an automatic flush bolt designed for the inactive (passive) leaf of double-leaf doors, specifically for left-side installation with a 22 mm faceplate. Hidden within the door leaf, the bolt is deployed automatically when the active leaf is closed, ensuring secure locking. It is suitable for use in fire-rated and smoke-control doors, providing additional safety compliance in both residential and commercial projects.

The standout feature of this model is its detachable bolt pin with a ball-end design, which significantly simplifies installation by allowing tool-free insertion and adjustment during fitting. This helps reduce installation time and lowers the risk of incorrect assembly on-site. Given its automatic actuation, concealed mechanism, and fire door approval, it is especially well-suited for bulk procurement by integrators, door manufacturers, or contractors outfitting multiple certified door sets.

Key Features

• Automatic activation ? bolt extends when active leaf is closed, unlocking when open


• Concealed installation ? hides entirely within passive leaf for aesthetics and security


• Detachable bolt pin with ball-end ? simplifies on-site mounting and adjustment


• Profiled latch with spring ? ensures reliable engagement and smooth operation


• Single routing required for body ? minimal machining, no cutting of corner required


• Adjustable strike and mounting plate ? fine-tune leaf-to-frame compression for tight seal


• Approved for fire and smoke doors ? meets additional safety and compliance requirements

Technical Specifications

• Type: Automatic flush bolt


• Installation Side: Left (passive leaf)


• Faceplate Width: 22 mm


• Mounting Location: Top of left passive leaf


• Mechanism: Concealed, automatic activation


• Bolt Pin: Detachable with ball-end


• Adjustment: Latch and strike length adjustable


• Approval: Fire-rated and smoke-control door applications

Applications

Designed for passive leaves in double-leaf fire-rated and smoke-control doors, typically installed in commercial, office, institutional, or residential buildings. Enables secure locking and code compliance for emergency exits, corridor doors, and compartmentalized access while remaining hidden from view. Compatible with OEM door assembly and large-scale fit-out projects requiring certified safety hardware.

Packaging & Shipping

Standard export packaging. Each unit includes the concealed bolt mechanism, detachable bolt pin, mounting hardware, and installation instructions.