Bolt and Swing Nut Sets

A Guide to Dog Bolt & Swing Nut Solutions for Marine Applications

Marine engineers and ship crew often depend on specialized components to ensure the safety, functionality, and durability of their vessels. Among these are Dog Bolts, Swing Nuts, and Eye Bolts, essential equipment in securing and fastening critical parts on ships, boats, and maritime structures. Designed specifically to withstand the demanding conditions of marine and offshore environments, these components are vital for efficient operations across various applications.
Whether you're responsible for maintaining an ocean-going vessel, a military ship, or a chemical tanker, understanding these components can make all the difference in managing your systems effectively. This guide explores their specific features, types, and how Dover Marine Manufacturing, a trusted name since 1957, delivers reliable engineering solutions to the marine sector.

Dog Bolt & Swing Nut
What Are They, and Why Are They Important?
A Dog Bolt is a robust fastener commonly used in applications that involve heavy-duty latching or clamping. Paired with a Swing Nut, this combination offers quick and reliable fastening solutions in maritime environments. Designed for simplicity and durability, this system excels in withstanding the forces of torque while ensuring a secure connection that doesn’t fail under pressure.

Applications in the Marine Industry
Dog Bolts and Swing Nuts are commonly used for tasks such as:

• Hatch and Door Securing: Ensuring watertight seals on ship hatches and doors

• Heavy-Duty Clamping: Securing critical parts exposed to vibrations and mechanical stress

• Offshore Drilling Equipment: Safeguarding components on oil rigs or marine vessels

• Maintenance Tasks: Providing engineers and crew with fast, efficient fastening solutions during inspections or repairs

The appeal of this combination is not just its solid grip—it’s the ease of disassembly when adjustments, repairs, or replacements are required, saving valuable time during operations or maintenance days.

Eye Bolt and Swing Nut
A Flexible and Reliable Pair
Eye Bolts, when paired with Swing Nuts, offer a level of flexibility that is especially desirable in the marine sector. Eye Bolts feature a closed-loop design at one end, making them incredibly versatile for securing ropes, lifting gear, or connecting components in dynamic environments.
Applications

• Load Handling: Eye bolts are often used for hoisting or securing equipment using pulleys or cables

• Safety Systems: They play a critical role in attaching lifelines or securing safety harnesses aboard ships

• Lifting Gear: Essential for moving heavy components like engine parts or cranes on offshore vessels

Manufacturers like Dover Marine ensure that Eye Bolt and Swing Nut systems are made to exacting specifications, accommodating the harsh exposure to saltwater, heavy loads, and extreme mechanical stress.

Tumble Bolt with Handle
A Practical Design for Easier Operations
The Tumble Bolt with Handle is yet another ingenious solution frequently used in marine operations. Renowned for their ergonomic design, tumble bolts are equipped with handles, simplifying installation and removal even when working with gloves or in confined spaces—a common occurrence aboard ships.
Benefits

• Time-Efficient Fastening**: Quick to tighten and release, saving time during repairs or shifts

• Durability: Designed to resist wear and tear in corrosive marine conditions

• Ergonomic: Handles provide better grip and ease use, reducing worker fatigue during long tasks

Tumble Bolt with Handle Economy
When cost efficiency is a priority, the Economy Tumble Bolt with Handle option provides a budget-friendly alternative without compromising on essential reliability and functionality. This variant ensures that even smaller operations or crews working on inland waterways vessels can access high-performing equipment for their fastening needs.
Trusted Manufacturing Since 1957 — Dover Marine
Finding high-quality, durable fastening solutions for maritime applications isn’t just convenient—it’s critical. With over six decades of experience, Dover Marine has been a trusted partner and innovator in the marine and offshore industries.
What Sets Dover Marine Apart?

• Exclusively Made in the USA

Every Dog Bolt, Eye Bolt, Tumble Bolt, and Swing Nut is manufactured exclusively in the United States, meeting strict quality standards.

• Versatility Across Industries

From ocean-going vessels and inland waterways ships to military vessels, chemical tankers, petroleum carriers, and offshore platforms, Dover Marine products are relied upon worldwide.

• Durability Designed for Marine Environments

Marine conditions are harsh, but Dover Marine products are designed to resist corrosion, withstand saltwater exposure, and excel under heavy mechanical stress for extended lifespans.
Why Choose Custom Fastening Solutions?
Every ship and offshore platform has unique requirements. Whether it’s a matter of accommodating specialized maintenance processes or creating watertight security for specific equipment, custom solutions ensure your fastening systems perfectly meet the challenges of marine environments.
By partnering with Dover Marine Manufacturing, marine engineers and ship crew can access hardware tailored to their exact specifications, ensuring the highest standards of efficiency and safety.
Prepared for the Challenges Ahead
For those maintaining or operating in the marine industry, reliable fastening systems like Dog Bolts, Swing Nuts, and Eye Bolts ensure smoother operations, reduced downtime, and safer environments. And when paired with a trusted manufacturer like Dover Marine, you’re not just securing your ship—you’re securing peace of mind.
Interested in learning more about Dover Marine’s range of components or designing a custom fastening solution? Reach out to their expert team today.