The fifth-wheel coupling provides the link between a semi-trailer and the towing truck, tractor unit, leading trailer or dolly. The coupling consists of a kingpin, a 2-or-3+1⁄2-inch-diameter (50.8 or 88.9 mm) vertical steel pin protruding from the bottom of the front of the semi-trailer, and a horseshoe-shaped coupling device called a fifth wheel on the rear of the towing vehicle. As the connected truck turns, the downward-facing surface of the semi-trailer (with the kingpin at the center) rotates against the upward-facing surface of the fixed fifth wheel, which does not rotate.
Some camper trailers also use a fifth-wheel configuration, with the coupling installed in the bed of a pickup truck as a towing vehicle; "fifth wheel" is therefore sometimes used as a synonym for such campers.
| Automotive quality management system | Implementing IATF16949-2016 |
| Quality management system (Services) | Implementing ISO9001-2015 |
| Technical standards | GB/T 31879-2015, GB/T 4606, GB/T 4607 |
| Warranty | 18 months since shipping date |
| Raw material | Q345 Pressed steel or Cast Steel Construction top plate, Forged alloy steel swing lock |
| Top plate | Pressed steel construction top plate with built-in, hardened front lock area |
| Lock | Forged, Machined, Heat-Treated alloy steel lock jaw with simple lock adjustment for extended wear life |
| Operating handle | Easy to pull operating handle fitted with secondary locking device |
| Mounting bolt | Brackets with ISO standard mounting bolt pattern and elongated mounting holes for easy field replacement |
| Maintenance | Simple locking mechanism with only 4 moving parts for easy maintenance, repair and replacement |
| Loading capacity | Not less than European standards |
| Grease | High efficient special grease is used to ensure good lubrication effect in various working environments and prolong the service life. |
| Sales volume (units） | 50,000+ per year |
| Overseas market | 30+ countries (Thailand, Austraulia, Singapore, Russia, Brazil, Malaysia, The Philippines, Indonesia, Saudi Arabia, UAE, Iraq, South Africa, Nigeria, Tanzania, Cameroon, Gabon etc) |
| Clients (overseas) | 40+ |
| Land area (square meters) | 25,000+ |
| Number of equipments (sets) | 200+ |
| Employees | 100+ |
| Engineers | 6 |
| Available certificates | FORM E, FORM A, COC, BV, SGS, SASO |
Comprehensive info of fifth wheels:
| Production series | forging 2", forging 3.5“, casting 2", casting 3.5" |
| Suitable king pin | 2", 3.5" or 50, 90 |
| Capacity 2" (50mm) king pin lock D-value | 20,000 kg Vertical Load 65,000 kg Gross Combination Weight D-Value 152 kN U-Value 20 Tonne |
| Capacity 3.5" (90mm) king pin lock D-value | 30,000 kg Vertical Load 80,000 kg Gross Combination Weight D-Value 200 kN U-Value 30 Tonne |
| Mounting (Slide bracket) height | 150 mm, 160 mm, 170 mm, 172 mm, 182 mm, 185 mm, 195 mm, 200 mm, 220 mm, 225 mm, 250 mm or 7”, 8”, 9”, 10” or 11” |
| Slide plate travel length | 8”, 12”, 16”, 24”, 36”, 48” |
| Swing type | Single swing type, double swing type |
| Application | Towing truck, tractor unit, leading trailer or dolly, light weight vehicles, camper trailers, multiple road condition |
| Interchangeable brands | JOST fifth wheels, SAF-HOLLAND fifth wheel, Fuwa fifth wheels, etc. |
| Replacements | JSK 35 DV 25, JSK39 DV 30, JSK 39 DV 35, JSK52, JSK35DVS, JSK 36DV, JSK 39 DV 28, FW20-150, FW20-185, FW28-150, FW28-185, FW0070, FW78Q, FW78A, FW78B, FW78ZB, FW78ZKB, FW78S, FW79S, FW79H, FW79F, GC 6, SK-S 36.20 PLUS H, SK-S 36.20 PLUS, SK-S 36.20 PLUS W, SK-S 36.20 PLUS D, SK-S 36.20 PLUS DW, SK-S 36.20 PLUS V, SK-S 36.20 PLUS VW, FW 3510, FW 3110, GES 20, SK-S 36.20 PLUS, SK-HD 38.36, SK-HD 38.36G, FW0E70, FW2E70, FW0100, FW0165, FW3510-TR, FW0E70-T, FW3540 + FW3140, FW7E40 |
| Colors | Shiny black, dark black, grey, blue, red, etc. As per requirement. |
| Standards implemented | IATF 16949, ISO9001-2015, GB/T 31879-2015, GB/T 4606, GB/T 4607 |
| Payment term | TT, LC, DP |
| Lead time | About 15~25 working days |
| MOQ | 10 pcs |
WONDEE forging type fifth wheel series:
| Item No. | Rated Vertical Load | D-value | Lengthways Swing Angle | Installation Height | King Pin Size | Weight |
| (kg) | (kn) | (a°) | (mm) | (mm) | (kg) | |
| FW50-FS01 | 20000 | 152 | 12 | 150.5 | 50 ( 2" ) | 126 |
| FW50-FS02 | 20000 | 152 | 16 | 173 | 50 ( 2" ) | 130 |
| FW90-FS01 | 25000 | 182 | 12 | 165 | 90 ( 3.5" ) | 140 |
| FW90-FS02 | 25000 | 182 | 15 | 175 | 90 ( 3.5" ) | 145 |
WONDEE casting type fifth wheel series:
| Item No. | Rated vertical load | D-value | Lengthways angle | Transverse swing angle | Installation height | King Pin Size | Weight |
| (kg) | (kn) | (a°) | (β°) | (mm) | (mm) | (kg) | |
| FW50-C01 | 25000 | 176 | 15 | 0 | 167.5 | 50 | 172 |
| FW50-C3038C1 | 28000 | 170 | 15 | 0 | 195 | 50 | 229 |
| FW90-C3038C1 | 36000 | 260 | 15 | 0 | 195 | 90 | 229 |
| FW90-C3038G1 | 40000 | 260 | 15 | 7 | 290 | 90 | 300 |