What Is a Flush Bolt—and Why Your Double Door Needs One
Double doors can make a striking feature in any home or commercial space. They create a grand entrance, improve accessibility, and offer flexibility in how a space is used. But for all their benefits, double doors require the right hardware to function correctly—and securely.
In most double door setups, only one door (called the active leaf) opens and closes regularly. The other side (the inactive leaf) usually remains closed. So how do you keep that second door securely shut?
That’s where flush bolts come in.
See It in Action
Want to understand how flush bolts work in a real setting? Watch our quick video walkthrough that explains where flush bolts are installed, how they function, and why they’re essential for double door setups.
What Does a Flush Bolt Do?
A flush bolt is a subtle yet essential component in double door configurations. It’s a locking mechanism fitted into the edge of the inactive door leaf. When engaged, the bolt extends into the door frame at the top, and often into the floor at the bottom, holding the door securely in place.
Unlike surface-mounted barrel bolts, flush bolts sit recessed inside the door. This makes them less visible, helping to maintain a clean, seamless look. For design-conscious homes and commercial spaces, this hidden detail keeps the focus on the overall aesthetic without compromising functionality.
Flush bolts operate manually. You simply slide the bolt up into the top jamb or down into the floor to lock the door, and reverse the motion to unlock. When both the top and bottom bolts are engaged, the inactive leaf stays firmly in place—allowing the active door to function without wobble, drafts, or misalignment.
Why Flush Bolts Matter for Double Doors
Without flush bolts, the inactive door leaf can’t stay secure. Even if it seems closed, a simple push or gust of wind could move it. This can misalign the doors, strain the hinges, and even damage your locks or frames over time.
Flush bolts not only hold the door steady but also help protect the overall integrity of your doorway. Whether you're installing French doors in a bedroom, grand timber doors at an entry, or sliding cavity units with swing panels, flush bolts provide the stability and reliability needed for long-term performance.
Choosing the Right Flush Bolt
Flush bolts come in different sizes to suit a range of door types. The most common lengths are:
-
150mm: Ideal for standard interior doors.
-
300mm: Recommended for taller, heavier, or exterior doors where added strength is required.
When selecting a flush bolt, consider the door’s height, weight, and intended use. External doors often benefit from longer bolts, while internal doors generally function well with the standard size.
In addition to size, you’ll also want to consider the finish. Your flush bolts should coordinate with the rest of your door hardware for a cohesive look. At Entry Point, we stock flush bolts from trusted brands like Zanda, which offer finishes such as:
-
Graphite Nickel
-
Matte Black
-
Satin Brass
-
Stainless Steel
These finishes pair beautifully with a wide range of door handles, hinges, and accessories, allowing you to match your hardware to your design scheme.
Need Help with a Double Door Setup?
Flush bolts may seem like a small detail, but they play a big role in both security and appearance. If you're building or renovating and considering double doors, our team can help you choose the right size and finish, and guide you on installation options.
At Entry Point, we specialise in premium door hardware for homes and commercial projects across Perth. Whether you're working with architects, cabinet makers, or fitout specialists, we’ll make sure your double door solution is both functional and visually refined.
Get in touch with Entry Point—Perth’s door hardware experts—for tailored advice on flush bolts, finishes, and double door configurations.
