Protecting your trailer’s kingpin from theft is critical. We researched and compared the most popular king pin locks on the market, evaluating them based on manufacturer specifications, published industry safety standards, and aggregated owner feedback. Our guide covers key factors like material strength, lock mechanism reliability, weather resistance, and ease of use. Whether you need a heavy-duty lock for a semi-trailer or a compact model for a fifth-wheel RV, we’ve analyzed the options to help you choose the right security device.
| Photo | Product | Score | Buy |
|---|---|---|---|
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Husky 5th Wheel King Pin Lock Best Overall Hardened steel, dual locking pins, weather-resistant cover |
9.0 | 🛒 Check Price |
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Trimax TML55 King Pin Lock Premium Security Hardened boron steel, shrouded lock core, corrosion-resistant |
8.7 | 🛒 Check Price |
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Master Lock 3790 King Pin Lock Best Value Hardened steel shackle, dual locking levers, weather-resistant |
8.4 | 🛒 Check Price |
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Reese Towpower 7016900 King Pin Lock Easy to use Zinc-plated steel, spring-loaded design, no-tools installation |
8.1 | 🛒 Check Price |
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Pro-Tect KPL-1 King Pin Lock Compact Design Hardened steel body, keyed-alike option, compact size |
7.8 | 🛒 Check Price |
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Curt 23500 King Pin Lock Heavy Duty Forged steel, dual locking pins, black powder coat |
7.3 | 🛒 Check Price |
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DLG AutoTrailer King Pin Lock Budget Pick Zinc alloy body, single locking pin, universal fit |
7.0 | 🛒 Check Price |
1. Husky 5th Wheel King Pin Lock: Best Overall
The Husky 5th Wheel King Pin Lock stands out in our evaluation for its well-engineered design. It uses hardened steel with a dual-pin locking system that provides excellent resistance to tampering. Based on owner feedback, the lock fits most standard kingpins securely, and the included weather-resistant cover helps prevent rust and freezing. In our comparison, it offers a strong balance of security and ease of use, making it a top choice for most trailer owners.
However, its solid construction adds weight, which may be a minor inconvenience for those who handle the lock frequently. Some users noted that the key can be stiff initially. If you need a lighter lock for occasional use or have a non-standard kingpin size, you might consider alternatives. But for overall reliability and confidence, this lock is hard to beat.
- Hardened steel construction resists cutting and sawing
- Dual locking pins provide redundant security
- Weather-resistant silicone cover protects lock mechanism
Pros: Very sturdy build quality; Easy to install and remove
Cons: Heavier than some competitors
2. Trimax TML55 King Pin Lock: Premium Security
The Trimax TML55 is a premium king pin lock designed for maximum security. It uses hardened boron steel and a shrouded lock core that shields the keyway from forced entry. In our research, this lock meets stringent security standards and is favored by owners who store trailers in high-theft areas. The corrosion-resistant finish adds durability, and the lock operates smoothly even after extended use.
That said, the premium comes at a cost, and the lock is more expensive than many alternatives. Additionally, key replacement is proprietary, which could be an inconvenience if you lose the key. If your trailer is parked in a low-risk environment, a more affordable lock may suffice. However, for those prioritizing maximum protection, the TML55 is a strong contender.
- Hardened boron steel resists bolt cutters and saws
- Shrouded lock core protects against drilling and picking
- Corrosion-resistant finish for outdoor use
Pros: Top-tier security features; Smooth locking mechanism
Cons: Higher price point; Limited key duplication options
3. Master Lock 3790 King Pin Lock: Best Value
The Master Lock 3790 offers a solid balance of security and affordability. It features a hardened steel shackle and dual locking levers that provide dependable protection for most trailers. Based on owner feedback, it fits well on standard kingpins and is easy to install. In our evaluation, it represents a great value for those who need a reliable lock without breaking the bank.
However, some owners report that the lock core can become stiff in freezing temperatures, requiring extra effort. Also, while it is durable for its price, it may not withstand determined theft attempts as well as higher-end models. If you live in a very cold climate or require maximum security, you might want to invest in a more rugged option. But for everyday use in moderate conditions, this lock is a smart choice.
- Hardened steel shackle resists cutting
- Dual locking levers for secure fit
- Weather-resistant coating for longevity
Pros: Excellent value for the price; Lightweight and easy to carry
Cons: Lock core may jam in cold weather; Not as heavy-duty as premium models
4. Reese Towpower 7016900 King Pin Lock: Easy to use
The Reese Towpower 7016900 is designed for convenience. Its spring-loaded locking mechanism allows for quick one-hand operation, making it a favorite among owners who frequently hitch and unhitch. The zinc-plated steel offers decent corrosion resistance, and the lock is lightweight enough to carry in a glove box. In our comparison, it scores high for ease of use.
On the downside, the construction is not as strong as hardened steel locks, and the spring mechanism may lose tension after extended use. It provides adequate security for low-risk environments, but we would not recommend it for high-theft areas or heavy-duty commercial use. If you prioritize speed and simplicity over maximum strength, this lock is worth considering.
- Spring-loaded locking mechanism for quick use
- Zinc-plated steel resists rust
- Tool-free installation and removal
Pros: Very easy to operate; Lightweight and compact
Cons: Less durable than hardened steel models; Spring can wear out over time
5. Pro-Tect KPL-1 King Pin Lock: Compact Design
The Pro-Tect KPL-1 is a compact king pin lock that fits trailers with limited clearance around the kingpin. It features a hardened steel body and offers a keyed-alike option, which is convenient if you use multiple Pro-Tect locks. In our evaluation, it performs adequately for light to medium security needs and is easy to store.
However, some owners report that the locking mechanism can be inconsistent, sometimes requiring wiggling to engage. Additionally, the finish is not highly weather-resistant, so rust may develop over time in wet climates. If you have a tight space or need a lock that matches others, this could work, but we suggest skipping it for long-term outdoor exposure or high-security applications.
- Hardened steel body resists cutting
- Keyed-alike option for multiple locks
- Compact size fits tight spaces
Pros: Small footprint for limited clearance; Good build for the size
Cons: Locking mechanism can be finicky; Not as weather-resistant as others
6. Curt 23500 King Pin Lock: Heavy Duty
The Curt 23500 is a heavy-duty king pin lock made from forged steel with a dual-pin system. It is built to withstand significant force, and the powder coat finish helps prevent rust. In our research, it appeals to owners who want a tough lock for commercial trailers or RVs stored in harsh conditions.
However, the lock’s bulk can make installation challenging on some kingpins, especially those with tight tolerances. Several owners reported that it required filing or adjustment to fit properly. Additionally, it is heavier than most, which may be a drawback for frequent use. If you have a compatible kingpin and need maximum strength, this lock is an option, but we recommend checking fitment carefully before purchase.
- Forged steel construction for strength
- Dual locking pins for extra security
- Black powder coat finish for corrosion resistance
Pros: Sturdy build; Good corrosion resistance
Cons: Difficult to install on some kingpins; Bulky design
7. DLG AutoTrailer King Pin Lock: Budget Pick
The DLG AutoTrailer King Pin Lock is a budget-friendly option for those who need a basic deterrent. It is made from zinc alloy and features a single locking pin. In our evaluation, it is easy to install and fits most standard kingpins, making it accessible for occasional use.
However, the materials are not as strong as hardened steel, and the lock is vulnerable to cutting or prying. Owner feedback indicates that the finish can rust quickly, especially in wet conditions. This lock is suitable only for low-risk environments where theft is unlikely. If you need real security, we advise investing in a higher-quality model. For minimal protection on a tight budget, it may suffice temporarily.
- Zinc alloy construction
- Single locking pin design
- Universal fit for most kingpins
Pros: Very affordable; Lightweight and easy to carry
Cons: Low durability and security; Prone to rust over time
Frequently Asked Questions
What is a king pin lock and why do I need one?
A king pin lock is a security device that attaches to the kingpin of a trailer to prevent unauthorized towing. It acts as a visible deterrent and physical barrier against theft. We recommend one for any trailer that is parked unattended, especially in public areas or overnight.
How do I choose the right king pin lock size?
Most king pin locks are designed to fit standard 2-inch or 3.5-inch kingpins. Check your trailer’s kingpin diameter and cross-reference with the lock specifications. Some locks offer adjustable or universal fit. We advise measuring your kingpin before purchasing to ensure compatibility.
Are king pin locks weather-resistant?
Many king pin locks feature weather-resistant coatings or covers to prevent rust and freezing. However, not all models are equally durable. In our research, locks with silicone covers or stainless steel components perform better in wet climates. For extreme weather, look for models with corrosion-resistant finishes.
Can a king pin lock be easily removed by thieves?
No lock is completely theft-proof, but quality king pin locks with hardened steel and shrouded keyways significantly increase the difficulty. Some cheap locks can be cut with bolt cutters. We recommend choosing a lock with high-security ratings and solid materials to maximize protection.
Do king pin locks interfere with the fifth wheel hitch?
Most king pin locks are designed to be removed before hitching, so they do not interfere with operation. However, some compact models can remain attached in certain hitches. Always check the manufacturer’s instructions to ensure safe clearance and avoid damage.
Our Verdict
After comparing specifications, security features, and owner feedback, our top pick is the Husky 5th Wheel King Pin Lock for its sturdy construction and reliable performance. For those seeking premium security, the Trimax TML55 is an excellent runner-up, offering advanced protection features. Choose based on your specific needs and budget.
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