This product has been off the shelf!
Share to:

2 Inch 50#


Product Description

2 inch 50# forging type fifth wheel for heavy duty Semi Trailer and truck Parts:

Fifth wheel (10)


Item No.

Rated                                             Vertical Load


Lengthways                  Swing Angle

Installation              Height

King Pin                                          Size













50 ( 2" )







50 ( 2" )







90 ( 3.5" )







90 ( 3.5" )



1. Production  :

5th  wheel and fifth wheel for heavy duty semi trailer and tractor

Forging type fifth  wheel, casting type fifth wheel

2. Load capacity:

20T, 25T, 28T, 36T, 40T.

3. Application:

Trailer , semi trailer , truck , tractor,   container

4. Size of 5th wheel:

 2 inch, 3.5 inch,   50mm, 90mm, 50# ,90# .

5. Material:

45# Steel for casting fifth wheel

Q235 Steel for forging fifth wheel and fabricated fifth wheel

6. Swing type:

Single swing type , double swing type.

7. Reference brand:

JOST, WONDEE, FUWA brand 5th   wheel

8. Color

Red, shinning black, dark black, grey,   blue, As requirement.

9. Warranty:

12 months since shipping date.

10. Related Certificate:

ISO9001; TS16949; COC; PVOC; CIQ; SONCAP;   BV; C/O; FORM E.

11. Lead time:

About 10~15 Working Days

 5th wheel (2)


 What is the heavy duty steel FIFTH WHEEL for semi trailer and truck:


The fifth wheel (5th wheel) is a kind of traction member used to pull the semi-trailer of the truck. The fifth wheel is commonly called the saddle, and the towing vehicle equipped with this fifth wheel is also called the saddle tractor. The 5th wheel mainly consists of a seat plate mainly composed of a seat cover, a saddle base and a locking mechanism, and a separation-connecting mechanism and a support.

5th wheel (4)

The 5th wheel's function:


The 5th wheel can not only bear part of the vertical mass of the semi-trailer, but also plays the role of towing the semi-trailer, and at the same time is the steering mechanism of the semi-trailer. The shape of the two sides of the seat cover is a streamlined shape with a wider middle part and narrower sides. A cross-shaped stiffener is welded under the seat cover, and a set of lubrication pipelines are also provided under the seat cover. According to its separation --- different connecting mechanism, it is divided into splint type and hook pin type.

The fixed 5th wheel is currently the most widely used one. Its support is fixed on the frame of the towing vehicle, and the 5th wheel allows a certain degree of freedom on the support.

5th wheel (7)

How Fifth wheel and semi-trailer unhooking:


When the tractor is connected to the semi-trailer and needs to be unhooked, the safety baffle should be pushed aside first, and then the handle should be pulled to move the locking block forward to the I-shaped gap away from the splint, the spring is compressed, and the front end of the splint is fixed. Pulled by the spring, they are brought together and pressed against the locking block. Then drive the towing car forward to complete the uncoupling of the semi-trailer. The landing gear of the semi-trailer should also be lowered before unhooking.

5th wheel (5)

The 5th wheel size specifications:

For the important link between the tractor and the semi-trailer, the type of the 5th wheel also has various types according to the different usage conditions of the vehicle. There are two main types of common 5th wheel, 50mm (2 inch) and 90mm (3.5 inch ), which are commonly referred to as 50# fifth wheel and 90# fifth wheel. Semi-trailers used for ordinary road transportation are usually equipped with 50.8mm king pin, while 90mm king pin trailers are mostly used for construction machinery transportation trailers and special trailers.

5th wheel (3)


The fifth wheel is classified according to the swing mode and its application:


The swing of the fifth wheel has two structures, according to the allowable degrees of freedom, there are single way swing type and double ways swing type. The common one is the single way swing type, that is, after the fifth wheel is connected to the trailer, a range of undulations is allowed according to the driving road conditions. The single way swing type fifth wheel can only make an octave longitudinal tilt around the pin axis. This type of fifth wheel has high driving stability, and is suitable for high-speed, light-load and high-mass semi-trailers running on better roads. It is mostly used in large container semi-trailers, high cargo platforms, and bulk freight semi-trailers.

For the transportation of large goods and heavy special equipment, the single swing type is far from meeting the needs. The lifting weight is usually one or two times or even several times higher than that of general road transportation. Therefore, the fifth wheel used in the heavy transportation field usually adopts the double swing type fifth wheel , That is, the fifth wheel can swing left and right in addition to the front and back swing, which protects the tractor girder under different road conditions during heavy transportation.

5th wheel (8)

 The fifth wheel is distinguished by material:

According to the materials used, the 5th wheel is divided into forging type fifth wheel and casting type fifth wheel. The general loading capacity includes 20T, 25T, 28T, 36T, 40T.


WONDEE supply various kinds of semi trailer fifth wheel more than 20 years: 

5th wheel (6) 

In addition to supplying different types of semi trailer 5th wheel, WONDEE also Supply different types of semi trailer components as below:

Wondee products collection



Xinhe Industrial Park, Xiamen, Fujian, China 361006





Copyrignt @ 2021 XIAMEN WONDEE AUTOPARTS CO., LTD. All Rights Reserved | Friendly Links: |