In architectural security, the Heavy Duty Tubular Deadbolt is favored for its “hidden” strength. Unlike standard latches that only keep a door closed, a deadbolt features a squared-off bolt that cannot be retracted by spring pressure. It must be manually operated by a turn or key, making it significantly harder to “jimmy” or “shimming” with a credit card or similar tool.

The “Heavy Duty” designation refers to the internal mechanical tolerances and the thickness of the bolt. Forged from high-tensile steel—often with a free-rotating internal pin to resist sawing—this deadbolt is designed for use on front doors, interconnecting garage doors, and secure storerooms. Despite its industrial-grade performance, its tubular body requires only a simple bore-hole installation, making it a favorite for both retrofitting and new builds.

Why the Heavy Duty Tubular Deadbolt is the Professional Choice

Hardened Steel Bolt: The core of the deadbolt is engineered to resist hacksawing and physical impact, providing a solid mechanical lock between the door and the frame.
Deep Bolt Throw: Typically featuring a 13mm to 16mm throw, this deadbolt engages deep into the door jamb, ensuring maximum resistance against “kick-in” attacks.
8mm or 5mm Spindle Compatibility: Available in multiple configurations to suit standard thumbturns or heavy-duty commercial 8mm spindles.
Reinforced Box Strike Plate: Unlike thin, decorative plates, the heavy-duty version includes a reinforced steel strike box that protects the timber frame from splintering under pressure.
Multiple Backset Options: Available in 64mm (2.5″) and 76mm (3″) sizes to match the aesthetic placement of existing door handles and locks.
Fire-Rated Integrity: Tested for use on 30 and 60-minute fire doors (FD30/FD60), ensuring that security does not come at the expense of life safety.

Technical Specifications

Feature	Specification
Material Build	Hardened Steel Bolt / Solid Brass or Steel Faceplate.
Lock Type	Tubular Mortice Deadbolt (Non-Spring).
Bolt Throw	13mm – 16mm (Extended Security).
Spindle Size	5mm (Residential) or 8mm (Commercial).
Backset Sizes	64mm or 76mm.
Finish Options	Satin Stainless, Polished Brass, Matte Black.

Professional Installation for Maximum Resistance

The effectiveness of a Heavy Duty Tubular Deadbolt depends entirely on the precision of its housing within the door and frame.

Centered Boring: Use a high-quality spade bit or Forstner bit to ensure the hole for the tubular body is perfectly horizontal. Any “tilt” will cause the deadbolt to bind, making it difficult to turn.
Strike Box Recessing: Do not skip the installation of the internal “dust box” or strike box. This component provides the structural reinforcement that prevents the bolt from bursting through the timber frame if the door is forced.
Long Security Screws: For the strike plate on the door jamb, discard the standard 20mm screws. Use 50mm to 75mm stainless steel screws that reach through the door frame and into the structural wall studs.
Alignment Check: Ensure there is a 1mm to 2mm clearance between the bolt and the strike plate. If the bolt “rubs” against the plate, it can cause the internal mechanism to wear prematurely or jam during seasonal door swelling.
Lubrication: Use a dry PTFE or graphite lubricant inside the mechanism. Avoid wet oils or WD-40, which attract dust and can gum up the heavy-duty springs over time.

A Discreet, High-Strength Barrier

The Heavy Duty Tubular Deadbolt is the ultimate “fit-and-forget” security upgrade. It offers the heavy-duty protection of a sashlock with the minimalist footprint of a tubular latch. By choosing a hardened-steel unit, you are investing in a durable, reliable barrier that provides peace of mind for both residential and commercial property owners.

This heavy duty tubular deadbolt is designed for maximum strength and security, making it an excellent choice for both residential and commercial applications. Measuring 76mm, it comes complete with a stainless steel (SSS) forend for added durability, corrosion resistance, and a clean, professional finish.

Built to withstand frequent use, the deadbolt provides reliable locking performance and enhanced protection for internal and external doors. Easy to install, it combines robust construction with long-lasting functionality, ensuring doors remain safe, secure, and stylish over time.