Semi Trailer Fifth Wheel
20+ years of experiences (since 2005)
Implementing ISO 9001-2015
Quality testing by an independent laboratory
Warranty: 18 months since shipping date
Unique lock-jaw/bar design: Easy & Safe locking
Stamped plate with Fabricated frame: Robust & Reliable
Technical standards: GB/T 31879-2015, GB/T 4606, GB/T 4607
Production volume (units）: 60,000+ per year
Fifth-Wheel Coupling: Connecting Semi-Trailers to Towing Vehicles:
The fifth-wheel coupling is the essential mechanism that links a semi-trailer to its towing vehicle, which may be a truck tractor, lead trailer, or dolly. This coupling system consists of two main components:
Kingpin – A vertical steel pin (typically 2-inch or 3½-inch diameter / 50.8 mm or 88.9 mm) mounted beneath the front of the semi-trailer.
Fifth Wheel – A horseshoe-shaped coupling device mounted on the towing vehicle, designed to secure the kingpin while allowing rotational movement.
When the truck turns, the trailer’s lower plate (with the kingpin at its center) rotates against the fixed fifth wheel’s upper plate, enabling smooth articulation without detachment.
Product Parameters：
Type | H | D-Value(KN) | Impose(kg) | Weight(kg) | Tilt Angle(U) | Total weight of | Kingpin Size |
XH-37C-150 | 150 | 152 | 20000 | 150 | 15° | 65000 | 50mm |
XH-37C-170 | 170 | 152 | 20000 | 155 | 15° | 65000 | 50mm |
XH-37C-185 | 185 | 152 | 20000 | 160 | 15° | 65000 | 50mm |
XH-37C-250 | 250 | 152 | 20000 | 175 | 15° | 65000 | 50mm |
XH-37C-300 | 300 | 152 | 20000 | 180 | 15° | 65000 | 50mm |
XH-38C-195 | 195 | 260 | 36000 | 228 | 15° | 70000 | 90mm |
The fifth wheel base is a critical component of a semi-trailer's coupling system, connecting the tractor (truck) to the trailer. It consists of several key parts that ensure secure attachment and smooth articulation. Below are the main fifth wheel base parts:
1. Fifth Wheel Plate (Coupling Mechanism)
The main platform that mounts onto the tractor’s frame.
Contains a locking mechanism (jaws) to secure the trailer’s kingpin.
Made of high-strength steel for durability.
2. Kingpin (Trailer Side)
A solid steel pin mounted on the trailer’s front underside.
Engages with the fifth wheel’s locking jaws to form the pivot point.
3. Locking Jaws & Release Handle
Upper & Lower Jaws: Clamp around the kingpin to secure the trailer.
Release Handle/Lock Lever: Allows the driver to disengage the fifth wheel for uncoupling.
4. Skid Plate (Wear Plate)
A replaceable low-friction surface (often greased) that reduces wear between the fifth wheel and trailer.
5. Mounting Brackets & Pivot Pins
Secures the fifth wheel to the truck’s frame.
Some designs allow sliding adjustment for weight distribution.
6. Air Lines & Electrical Connectors (for ABS/Brakes)
Pneumatic and electrical connections for trailer brakes and lights.
7. Safety Latch (Secondary Lock)
Prevents accidental release of the kingpin.
8. Grease Fittings (Zerk Fittings)
Allows lubrication of the fifth wheel to reduce friction.
Common Fifth Wheel Types:
Fixed Fifth Wheel: Permanently mounted to the tractor.
Sliding Fifth Wheel: Adjustable for weight distribution.
Oscillating Fifth Wheel: Allows slight tilting for uneven terrain.
Maintenance Tips:
Regularly inspect locking jaws and kingpin for wear.
Keep the skid plate lubricated.
Check for cracks or stress in the mounting brackets.
Shipment:
