A hinge bolt (also called a security stud or dog bolt) is a fixed metal pin installed on the hinge side of a door or gate. Its job is to prevent the door from being removed if the hinge pins are taken out or defeated. Hinge bolts are most commonly used on outward-opening doors, security doors, metal gates, and fire or industrial doors.
A hinge bolt does not hold the hinge together and does not replace the hinge pin. Instead, it creates a secondary locking point between the door and the frame.
The bolt is fixed to one side (usually the door leaf)
A matching receiver hole is drilled in the frame
When the door closes, the bolt slides into the hole
Even if the Hinges fail or pins are removed, the bolt locks the door into the frame.
The hinge bolt is visible
It protrudes from the door edge near the hinge
It is not engaged with the frame
As the door swings shut, the bolt aligns with the receiver hole
The bolt enters the hole smoothly
No spring or moving parts are involved
The bolt is fully seated in the frame
The door cannot be lifted or pulled away from the hinge side
Removing hinge pins has no effect on door security
This creates a shear-resistant connection that defeats hinge-side attacks.
On outward-opening doors:
Hinges are exposed
Hinge pins can be attacked or removed
The door could be lifted out once pins are gone
Hinge bolts eliminate this weakness.
Hinge bolts:
Require no keys
Have no moving mechanisms
Do not affect normal door operation
They add security passively and reliably.
Solid metal stud
No movement
Most common and durable type
Slight axial movement
Helps with alignment tolerance
Used where installation precision is harder to maintain
Built directly into the hinge leaf
Cleaner appearance
Often used in commercial or metal door systems
Hinge bolts are installed:
Near each hinge
Usually one bolt per hinge
On the hinge side edge of the door
For tall or heavy doors, multiple hinge bolts are used.
Correct function depends on:
Precise drilling of the receiver hole
Proper door-to-frame clearance
Accurate hinge positioning
Poor alignment can cause binding or prevent full engagement.
Hinge bolts are usually made from:
Hardened steel
Stainless steel for corrosion resistance
The goal is maximum resistance to:
Shear force
Bending
Sawing or prying
Larger diameter hinge bolts provide:
Higher shear strength
Better resistance to forced entry
Longer service life in heavy doors
Hinge bolts are a backup security feature, not a load-bearing component. Hinges still carry the door’s weight and control movement.
Hinge bolts do not secure the latch side. A proper lockset is still required for full security.
They are also widely used in:
Residential outward-opening doors
Utility rooms
Equipment enclosures
Industrial gates
For tall or heavy doors, multiple hinge bolts are needed to prevent twisting or prying.
Hinge bolts prevent door removal if hinges are attacked
They work by interlocking the door with the frame
Engagement happens automatically when the door closes
They are passive, durable, and low-maintenance
Especially important for outward-opening doors
Hinge bolts work by creating a fixed mechanical interlock between the door and the frame on the hinge side. When the door closes, the bolt seats into a receiver hole, preventing the door from being removed even if hinge pins are compromised. Simple in design and highly effective, hinge bolts are a critical security feature for outward-opening doors, metal gates, and high-risk installations where hinge-side protection is essential.
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