Trailer Accessories

Company Introduction

The company was established in 2016 and has undergone 7 years of development. We adhere to the core values of "innovation, quality, integrity, and win-win", constantly breaking through ourselves and pursuing excellence. Located at the foot of the world-renowned Shuibo Liangshan Mountain, the section of National Highway 220 from Jinan to Zhengzhou is a prime location. The Beijing Hangzhou Grand Canal and the South to North Water Diversion Project flow downstream in the east of the city, while the Beijing Kowloon Railway runs directly from north to south in the west. There are three high-speed entrances and exits in the east, west, and north of Liangshan, with a superior geographical location and convenient and fast transportation.

Why Choose Us

01/

Our factory
Located at the foot of the world-renowned Shuibo Liangshan Mountain, the section of National Highway 220 from Jinan to Zhengzhou is a prime location. Our company is a comprehensive production enterprise that integrates processing, manufacturing, and installation. We have strong mechanical processing capabilities, strong technical strength, and complete testing methods.

02/

Our product
Special vehicle accessories such as disc brake axle, drum brake axle, air suspension, mechanical suspension, semi-trailer support leg, traction pin, air storage cylinder, etc.

03/

Production equipment
Xiang Hengmai CNC sawing machine, hydraulic gate type shearing machine, screw compressor, frozen compressed air dryer, open fixed table press, Xuzhou pressure machinery hydraulic press, four column hydraulic press, suspension double gun automatic welding machine, shot blasting cleaning equipment, centrifugal ventilation fan, 2 sets of Dehong environmental protection spraying equipment, 15 sets of secondary protection welding machines, and 1 set of environmental protection centralized welding smoke purification treatment equipment.

04/

Our service
We adhere to the policy of implementing customer needs and expectations, carrying out customer satisfaction work, implementing the goal of quality first, controlling product production and market, timely communicating with customers in case of after-sales issues, and providing solutions.

First 12 Last 1/2

What Is Semi-trailer King Pin

Frequently referred to as the ‘pivot point between the tractor and semi-trailer,’ the semi-trailer king pin is the part used to connect a semi-tractor and a semi-trailer. A semi-trailer king pin may resemble any of the above images but always shares a few key features. One side of the semi-trailer king pin is always welded to the semi-trailer. This is why semi-trailer king pins are often considered a ‘trailer solution’ rather than a ‘truck solution.’ They are always fixed to the trailer and then coupled with the tractor using a fifth wheel coupling device. Every semi-trailer king pin has a tapered section that is narrower in width than the sections above and below it. This is where the fifth wheel locks around the semi-trailer king pin to provide a secure coupling. By making the areas above and below the tapered area wider, manufacturers ensure another layer of protection, minimizing the potential that a semi-trailer king pin could slip out of a fifth wheel’ s coupling mechanism.

Advantages of Semi-trailer King Pin

Towing stability

By providing a secure connection point between the trailer and the tractor, the semi-trailer king pin enhances towing stability, reducing sway and improving handling during transportation.

Load distribution

The semi-trailer king pin helps distribute the weight of the trailer evenly on the tractor's fifth wheel, optimizing load distribution and reducing the risk of overloading or unbalanced cargo.

Durability and strength

Semi-trailer king pins are typically made from high-strength materials, ensuring durability and reliability under heavy loads, constant articulation, and road vibrations.

Safety

Semi-trailer king pins are designed with safety features such as locking mechanisms, alignment indicators, and torque specifications to ensure secure attachment and safe operation during towing.

How to Choose a Semi-trailer King Pin

Durability

A semi-trailer king pin is only as good as its lifespan. This is an integral component for any rig, and should the semi-trailer king pin fail, your trailer cannot move. That’ s why it’ s important to look for a semi-trailer king pin with proven durability. A semi-trailer king pin made from high-quality steel is likely to last significantly longer than a semi-trailer king pin manufactured with poor-quality materials. We’ ll talk more about manufacturing requirements and standards below, but how a product is manufactured can tell you a lot about how it will perform. Choose semi-trailer king pins from manufacturers with safe, reliable manufacturing standards and safety requirements. Does the manufacturer stand behind its product with a warranty or stringent manufacturing standards? If not, you may have a problem finding a semi-trailer king pin that can stand up to long hours of wear and tear on the road.

Safety

Perhaps the most important feature of any semi-trailer king pin is its ability to keep the operator and the rig safe. Choose semi-trailer king pins from reputable manufacturers with a long track record of safe manufacturing practices. Quality manufacturers will be happy to provide you with the information you need to verify the safety of their products.

Local standard compliance

Every trailer oem has its own international standards. Your trailer must meet those standards to ensure safe, compliant hauling in your area. To ensure you’ re in compliance, first find a manufacturer that produces semi-trailer king pins according to your local standards, and then verify their compliance. A great manufacturer will prove with data how their semi-trailer king pins meet established performance requirements.

Basic Knowledge About Semi-trailer King Pin

A semi-trailer king pin is installed on a semi-trailer and cooperates with a fifth wheel on a tractor to realize hooking up and dropping the semi-trailer and the tractor. The semi-trailer king pin is one of key parts connecting the tractor and the semi-trailer. The welded semi-trailer king pin is directly welded to the skid plate of the semi-trailer and cannot be replaced. The raw material of this kind of semi-trailer king pin is generally 20CrMnTi. It needs surface carburizing and quenching treatment to enhance wear resistance of its surface. The optional skid plate thickness is 8mm, 10mm, 12mm, 14mm and 16mm. The bolted semi-trailer king pin consists of a retention plate, a semi-trailer king pin (interchange head) and self-securing bolts. There are also two types of bolted type semi-trailer semi-trailer king pins: 50# (2”) and 90# (3.5”).

The bolted semi-trailer king pin is to weld the retention plate on the semi-trailer skid plate, and then fix the interchange head on the retention plate with self-securing bolts. When the bolted semi-trailer king pin is worn or accidentally damaged or must be replaced duo to other reasons, remove the eight bolts and replace a new interchange head. It’ s easy to maintain. The raw material of this kind of semi-trailer king pin generally adopts 40Cr and undergoes quenching and tempering treatment. The optional skid plate thickness is 8mm, 10mm, 12mm, 14mm and 16mm.

Precautions for Using Semi-trailer King Pin

Different semi-trailers have different loading designs, and the D-value of the semi-trailer king pin must meet the semi-trailer’ s design requirements to ensure safety of the vehicle. If the selected semi-trailer king pin does not match the thickness of the skid plate, the semi-trailer king pin cannot be properly matched with the 5th wheel, or cause abnormal wear of the semi-trailer king pin.

For welding a semi-trailer king pin, preheat at the welding position before welding, with the preheating temperature within the range of 200 ~ 300℃, and then use CO2 gas shielded welding to weld. Note: Welding is not allowed within the range of Φ110mm on the upper surface of the semi-trailer king pin. Before welding, preheat the welding position of the retention plate. The preheating temperature is within the range of 200-300℃. The welding method is the same as that of a welded semi-trailer king pin. After cooling, use self-securing bolts to lock the interchange head. The reference tightening torque is 190NM. Check the semi-trailer king pin for defects such as scars, premature wear, cracks, etc. Measure the diameter of the semi-trailer king pin and replace it in time if it reaches the wear limit. Check the skid plate for scars, distortion and foreign objects, otherwise it will cause abnormal wear of the semi-trailer king pin. Check whether any self-securing bolt is loose or broken. Otherwise, replace the self-securing bolt and tighten it according to the specified torque. Regularly check the above items according to the instruction manual of each automobile manufacturer.

During the running of a semi-trailer, the semi-trailer king pin rotates relative to the fifth wheel, causing the semi-trailer king pin to wear. Adjust the position of the lock bolt of the fifth wheel to eliminate the gap between the semi-trailer king pin and the lock hook. The semi-trailer king pin must be replaced when the wear of the semi-trailer king pin reaches the wear limit. During initial use, add an appropriate amount of grease around the end of the semi-trailer king pin. After the vehicle is used for a period of time, due to the frequent drops and hooks of the tractor and semi-trailer, necessary maintenance shall be carried out for the semi-trailer king pin: remove the oil sludge on the semi-trailer king pin (the oil sludge contains a lot of sand, which will aggravate the wear of the semi-trailer king pin) and supplement new grease.

What Is Semi-Trailer Plate Spring

The special leaf spring for semi-trailers, as a key component specially designed for heavy-duty cargo vehicles, has been widely recognized and applied for its excellent cargo carrying capacity and non deformation characteristics. The special leaf spring for semi-trailers is made of high-strength and high toughness materials, which enables it to withstand huge loads. During the transportation of goods, whether heavy or light, leaf springs can maintain stable support performance, ensuring the safety and stable driving of the vehicle.

Advantages of Semi-Trailer Plate Spring

01.

Durability

Semi-trailer plate springs are known for their durability and ability to handle heavy loads. They’re able to withstand the stress of constant weight and movement, making them ideal for use in commercial and heavy-duty trailers.

02.

Cost-effective

Compared to other types of suspension systems, semi-trailer plate springs are relatively inexpensive to manufacture and repair. This makes them an affordable option for many trailers, especially those used for commercial purposes.

03.

Simplicity

Semi-trailer plate springs are simple in design and construction, making them easy to install and maintain. They do not require complex hydraulic or pneumatic systems, and can be repaired with basic tools and equipment.

04.

Durability and strength

Semi-trailer plate spring is typically made from high-strength materials, ensuring durability and reliability under heavy loads, constant articulation, and road vibrations.

Choosing the Right Type of Semi-Trailer Plate Spring for Your Truck

Though there are a variety of semi-trailer plate springs available, the semi-trailer plate spring configuration you choose will depend on a number of factors. Considerations include your truck’ s payload, carrying capacity, size, weight and type.

Single-leaf also known as monoleaf is the most popular type for standard chassis configurations on light trucks or passenger cars. The single leaf’ s attached to the front and back truck axles, with one main contact point along its length. It provides more area to add more weight without the frame bending or snapping. When used with standard chassis configurations, it doesn’ t create much frame interference because it’ s relatively narrow compared to other types. Multileaf or multiplier springs are most commonly used with long-haul trucks, including wheel towers and front ends for dump trucks. They add length and strength to the suspension system and help distribute weight evenly across the axles. Multisemi-trailer plate springs consist of multiple semi-trailer plate springs of varying lengths that are stacked and staggered to keep heavier loads stabilized. The various semi-trailer plate springs allow you to shift trucks’ centers of gravity. Twin semi-trailer plate springs, also called dual semi-trailer plate springs, are normally used for tractor-trailers. These springs can be attached to the front or rear of the truck to handle higher payloads. Their use enables more even weight distribution across the two axles without filling bed, cab or trailer space. Open-eye semi-trailer plate springs are used for some of the heaviest materials because of their wide-angle connections. They can be bolted to the sides of an entire trailer frame to offer more stability than other types.

Precautions When Replacing Semi-Trailer Plate Spring

Weather, aging and weight overload can deteriorate your springs over time. Inspect the semi-trailer plate springs on your trailer at least once every 12,000 miles or when you notice any sagging, corrosion, cracks or uneven riding. Look at each eye of the spring and note any cracks here and near the mounting plates. Check for corrosion and rust on all sides of the spring. Assess any gaps between leaves, which indicate wear and overload. Wipe your semi-trailer plate spring and mounting plates clean and pat them dry regularly to minimize the chance for buildup. Lubricate them as needed to prevent premature wear and increase their longevity.

Always replace your trailer springs in pairs for a balanced load. Choose your replacement by noting your axle capacity, the number of leaves on your existing springs and what type and size your springs are. Most vehicle axles have the capacity rating listed on a sticker or plate, but you can also check in your owner's manual. Some manufacturers may also have specific axle information available on their websites. While you measure the spring, count how many leaves are on it. The more leaves it has, the more supported it is — but too many leaves will make your suspension too rigid. semi-trailer plate springs are typically mono-leaf, meaning they have only one leaf, or multi-leaf with clips between each layer. There should be no gaps between multi-semi-trailer plate springs. Once you've removed your semi-trailer plate spring, figure out what type you're working with. In some cases, you might only need to replace the bushings if your springs are still intact and aren't buckling, corroded or elongated.

How to Measure Semi-Trailer Plate Spring

01/

Jack up your trailer
Jack up your trailer far enough that the axle is hanging freely, and you can comfortably remove and replace the semi-trailer plate springs. Do not place the jack on the suspension.

02/

Remove the spring
The most accurate way to measure a semi-trailer plate spring is without any load-bearing on it. Remove and measure one spring at a time so the other spring can keep the suspension in place. You may need special tools to remove damaged nuts, bolts and mounts.

03/

Measure the length
Measure the spring's length with a standard tape measure placed from the center of one eye to the center of the eye on the opposite end.

04/

Measure the width
Measure the width by placing a tape measure from the bottom of the bottom leaf to the top of the top leaf.

05/

Take A and B measurements
Your A and B measurements are the length between the center point and each eye. For example, the A measurement is the length between the center point and the eye on the right side, while the B measurement is on the left.

06/

Measure the arch
The spring arch changes over time, so measuring it is a good way to understand how it wears down and what size to look for as a replacement. Flip the spring upside down and use a standard tape measure to measure from the floor or table to the first leaf.

Our factory

FAQ

Q: What is a semi-trailer king pin?

A: A semi-trailer king pin is a crucial component that connects the trailer to the tractor unit, allowing for articulation and steering control during towing.

Q: What is the purpose of a king pin?

A: The king pin serves as the pivot point between the semi-trailer and the tractor, enabling the trailer to articulate and follow the path set by the tractor.

Q: How does a king pin function?

A: The king pin fits into the fifth wheel coupling on the tractor, allowing for vertical movement and rotation to accommodate turns and uneven road surfaces.

Q: What are the signs of a worn-out king pin?

A: Signs of a worn-out king pin may include excessive play or movement, unusual noises during towing, uneven tire wear, and difficulty steering the trailer.

Q: Can king pins be lubricated?

A: Yes, king pins should be lubricated with high-quality grease to reduce friction, prevent wear, and ensure smooth articulation between the trailer and tractor.

Q: What are the safety considerations when inspecting king pins?

A: Safety considerations include chocking the wheels, ensuring the trailer is properly supported, and following manufacturer guidelines for inspection and maintenance procedures.

Q: How are king pins replaced?

A: King pins are replaced by removing the old pin, installing a new one, and ensuring proper alignment and torque specifications to maintain structural integrity and safety.

Q: Are there different types of king pins available?

A: Yes, there are different types of king pins, including standard king pins, greasable king pins, and heavy-duty king pins designed for specific applications and load capacities.

Q: What are the weight ratings for king pins?

A: King pins are rated based on their load-carrying capacity, with weight ratings ranging from 20,000 to 40,000 pounds or more, depending on the trailer's design and intended use.

Q: How do king pins contribute to towing stability?

A: King pins contribute to towing stability by providing a secure connection between the trailer and tractor, minimizing sway, improving handling, and enhancing overall control during towing.

Q: What are semi-trailer leaf springs?

A: Semi-trailer leaf springs are suspension components that support the weight of the trailer and provide a cushioning effect to absorb road shocks and vibrations.

Q: How do leaf springs work?

A: Leaf springs consist of multiple curved metal strips (leaves) stacked together, which flex and compress to absorb bumps and maintain the trailer's ride height.

Q: What are the common types of leaf springs used in semi-trailers?

A: Common types of leaf springs include multi-leaf springs, parabolic springs, and air suspension systems, each offering different load capacities and ride characteristics.

Q: How often should leaf springs be inspected?

A: Leaf springs should be inspected regularly as part of routine maintenance, checking for signs of wear, cracks, sagging, or misalignment that may affect suspension performance.

Q: Can leaf springs be repaired or should they be replaced?

A: Depending on the extent of damage or wear, leaf springs can be repaired by re-arching or adding leafs, but severe damage may require replacement for safety and performance reasons.

Q: How are leaf springs replaced?

A: Leaf springs are replaced by removing the old springs, installing new ones, and ensuring proper alignment, torque, and suspension settings to maintain ride quality and safety.

Q: How do leaf springs contribute to load distribution?

A: Leaf springs help distribute the weight of the trailer evenly across the axles, improving stability, handling, and reducing the risk of overloading or uneven tire wear.

Q: Can leaf springs be upgraded for better performance?

A: Yes, leaf springs can be upgraded with heavier-duty or adjustable springs to enhance load capacity, ride comfort, handling characteristics, and overall suspension performance.

Q: What maintenance is required for leaf springs?

A: Regular maintenance of leaf springs includes lubrication of pivot points, inspection for wear and damage, checking alignment, and ensuring proper torque on mounting hardware.

Q: How do leaf springs affect towing safety?

A: Properly maintained leaf springs contribute to towing safety by providing stable suspension, reducing sway, improving handling, and enhancing overall control of the trailer during towing.

We're professional trailer accessories manufacturers in China, specialized in providing high quality products with low price. We warmly welcome you to wholesale or buy discount trailer accessories from our factory.

trailer garden hose accessories, trailer cost effective trailer accessories, trailer hunting trailer accessories