A strong trailer king pin needs to match the trailer’s specified collar and bolster dimensions, with suitable material and installation requirements for the intended fifth-wheel connection. Buyers Products KP20038 is a well-documented choice for buyers seeking a 2-inch pin with a 0.38-inch bolster plate: its listing identifies forged AISI 8630 steel, heat treatment, and hardness. This roundup also includes WA15 5050 replacements, a 0.5-inch bolster-plate option, and a US-made Mytee Products pin.
The listed products differ in fitment references, materials, warranty information, and how much is specified, so a familiar model name alone is not enough to confirm compatibility. Check your trailer or existing pin specifications before ordering, and have any weld-on replacement installed appropriately.
Buyers Products KP20038 is the best overall pick in this set for a buyer whose trailer calls for a 2-inch king pin and 0.38-inch bolster plate. Its listing specifies forged AISI 8630 alloy steel, heat treatment to 302–363 BHN, and 150,000 PSI ultimate strength, giving more material detail than most alternatives. It is a weldable pin, so confirm the trailer’s required dimensions and installation procedure before choosing it; it is not a universal fit simply because the collar is 2 inches.
Our Top Picks
Best OverallSpecifies a 2-inch pin, 0.38-inch bolster plate, forged AISI 8630 steel, 302–363 BHN hardness, and 150,000 PSI ultimate strength.
View on Amazon
Thicker PlatePairs a 2-inch forged 4140-quality steel king pin with a 0.5-inch bolster plate and lists a three-year manufacturer warranty.
View on Amazon
US-Made OptionMade in the USA from 8630 alloy steel, with listed 150,000 PSI ultimate strength, hardness checks, magnetic-particle inspection, and weldability.
View on Amazon- Broad Fitment DETYI WA15 5050
Compare King Pins by Fit and Installation
| # | Product | Material | Material Type | Buy |
|---|---|---|---|---|
| 1 | 1. Buyers Products KP20038Best Overall | Alloy Steel | Alloy Steel | View on Amazon |
| 2 | 2. Tulga Fifth Wheel THLD2Thicker Plate | Alloy Steel | Alloy Steel | View on Amazon |
| 3 | 3. Mytee Products KingpinUS-Made Option | — | — | View on Amazon |
| 4 |  4. DETYI WA15 5050Broad Fitment | Carbon Steel | Carbon Steel | View on Amazon |
| 5 |  5. ELSOON WA15 5050WA15 5050 dimension match | Alloy Steel | Alloy Steel | View on Amazon |
| 6 |  6. YuShaTra WA15 5050Multi-reference WA15 replacement | — | — | View on Amazon |
| 7 | 7. Spryflower WA15 5050WA15 5050 secure-fit replacement | — | — | View on Amazon |
Detailed Reviews: Best King Pin For Trailer
#1 · Best Overall
1. Buyers Products KP20038
- Material: Alloy Steel
- Material Type: Alloy Steel
Best for: Forged-steel fifth-wheel replacement.
Why it ranks #1: Specifies a 2-inch pin, 0.38-inch bolster plate, forged AISI 8630 steel, 302–363 BHN hardness, and 150,000 PSI ultimate strength.
Forged AISI 8630 steel with heat treatment to 302–363 BHN gives this Buyers Products king pin a concrete strength profile for fifth-wheel coupling. Its 2-inch SAE pin and 0.38-inch bolster plate make it a focused option for buyers matching those dimensions who want a weldable replacement.
The AISI 8630 forging and stated 150,000 PSI ultimate strength give buyers specific material and strength information when selecting a fifth-wheel coupling component. Heat treatment maintains hardness at 302–363 BHN, while the 2-inch SAE pin and 0.38-inch bolster plate identify the dimensions to match against the trailer assembly. Because it is weldable, installation is a welded connection rather than a bolt-in swap; its 13-pound weight is also useful to account for during handling.
- Forged from AISI 8630 steel
- Heat-treated to 302–363 BHN
- Stated 150,000 PSI ultimate strength
- 2-inch pin with 0.38-inch bolster plate
- Weldable construction calls for a welded installation, not a bolt-in replacement.
Skip it if you need a bolt-in king pin; this listing specifies a weldable component rather than a bolt-on installation.
Buyers matching a 2-inch SAE pin and 0.38-inch bolster plate can consider this forged, heat-treated option for a fifth-wheel coupling. Its weldable format is the key boundary: plan for welded installation rather than a bolt-in change.
Full product details
| Brand | Buyers Products Company |
|---|---|
| Color | Black |
| Compatible Groove Diameter | 2 inches |
| Included Components | King Pin |
| Item Dimensions | 7.95 x 7.95 x 4.25 inches |
| Item Weight | 13 pounds |
| Manufacturer | Buyers Products |
| Material | Alloy Steel |
| Model | KP20038 |
| Size | 0.38" Bolster Plate Thickness |
| Size Name | 0.38" Bolster Plate Thickness |
| Thread Size | 2 inches |
Listed on Amazon as: Buyers Products KP20038 Forged Trailer King Pin, 2-Inch, 0.38-Inch Bolster Plate Thickness, Weldable, Provide Strength and Reliabilty to Your Fifth Wheel, 5th Wheel Accessories
View on Amazon#2 · Thicker Plate
2. Tulga Fifth Wheel THLD2
- Material: Alloy Steel
- Material Type: Alloy Steel
Best for: Half-inch plate weld-on fit.
Why it ranks #2: Pairs a 2-inch forged 4140-quality steel king pin with a 0.5-inch bolster plate and lists a three-year manufacturer warranty.
A 0.5-inch bolster plate sets this Tulga Fifth Wheel kingpin apart for buyers seeking a thicker plate dimension than the listed 3/8-inch options. Its forged 4140-quality steel and 2-inch size provide material and fit details for a heavy-duty, weld-on fifth-wheel hitch replacement.
The listing describes forged 4140-quality steel under European Union Standards ECR 55 quality certification, giving buyers a stated material and quality reference for a trailer hitch component. A 2-inch kingpin is identified for 2-inch fifth-wheel hitches, while the 0.5-inch bolster plate defines the plate thickness to compare with the existing assembly. The weld-on format points to a welded installation workflow, so the dimensions and installation method both matter when planning a replacement.
- Forged 4140-quality steel
- ECR 55 quality certified
- 2-inch kingpin for 2-inch fifth-wheel hitches
- 0.5-inch bolster plate
- The weld-on design requires welded installation rather than a bolt-in swap.
Skip it if you need a 3/8-inch bolster plate; this Tulga kingpin specifies a 0.5-inch plate instead.
This is a fit-oriented choice for buyers with a 2-inch fifth-wheel hitch assembly calling for a 0.5-inch bolster plate. Its forged steel and weld-on format suit a welded replacement workflow, not a bolt-in installation.
Full product details
| Brand | Tulga Fifth Wheel |
|---|---|
| Compatible with Vehicle Type | Trailer |
| Included Components | Kingpin |
| Manufacturer | Tulga Fifth Wheel |
| Part Number | THLD2 |
| Manufacturer Warranty Description | 3 Years Manufacturer Warranty |
| Material | Alloy Steel |
| Model Number | THLD2 |
Listed on Amazon as: Kingpin 2" for Trailer Fifth Wheel Hitches Heavy Duty Weld on Semi Trailer Kingpin with 0.5 Bolster Plates
View on Amazon#3 · US-Made Option
3. Mytee Products Kingpin
Best for: On-road mushroom-pin replacement.
Why it ranks #3: Made in the USA from 8630 alloy steel, with listed 150,000 PSI ultimate strength, hardness checks, magnetic-particle inspection, and weldability.
A stated 150,000 PSI ultimate strength and 8630 alloy steel define the Mytee Products weld-on kingpin for buyers replacing a fifth-wheel mushroom pin. Its listing also notes magnetic-particle inspection and Brinell hardness checks, while explicitly limiting use to applications that are not off road.
The 8630 alloy steel construction, with 4320H steel also listed as available, gives buyers material information for choosing this weld-on component. Mytee states approximately 150,000 PSI ultimate and 115 PSI yield strength, plus 100% Brinell hardness checking and magnetic-particle inspection. Those inspection details help characterize the part’s verification process, while its mushroom-pin description identifies the type. The explicit not-for-off-road limitation makes intended operating conditions a necessary part of the selection decision.
- Made from 8630 alloy steel; 4320H steel is also listed as available
- Approximately 150,000 PSI ultimate strength stated
- 100% Brinell hardness checked
- Magnetic-particle inspected and weldable
- The listing explicitly says this kingpin is not for off-road use.
Skip it if you operate off road; this Mytee kingpin is explicitly listed as not for off-road use.
On-road trailer owners seeking a weld-on mushroom kingpin can weigh its listed alloy steel, strength figures, and inspection checks. The decisive boundary is operating environment: the product is specifically not for off-road use.
Full product details
| Brand | Mytee Products |
|---|---|
| Color | Silver |
| Compatible Groove Diameter | 0.38 inches |
| Item Weight | 14 pounds |
| Manufacturer | Mytee Products |
| Screw Head Style | Mushroom |
| Size | 1 – Pack |
| Size Name | 1 – Pack |
Listed on Amazon as: Mytee Products Kingpin Weld On for 5th Wheel Trailer 0.38" Made in USA
View on Amazon#4 · Broad Fitment
4. DETYI WA15 5050
- Material: Carbon Steel
- Material Type: Carbon Steel
Best for: Cross-reference replacement option.
Why it ranks #4: Lists WA15 5050 replacement fitment and cross-references Dayton, Batco, Spicer, and Standard numbers; installation hardware is included.
Compatibility with WA15 5050 and several named OEM references gives this DETYI kingpin a useful replacement-selection advantage. The listing identifies Dayton, Batco, Spicer, and Standard numbers, while its 2-inch pin and 1/2-inch bolster plate specify the dimensions buyers can use to evaluate a trailer match.
The cross-reference list includes WA15 5050, Dayton 11-0212, Batco 11-200, Spicer 13101, and Standard 20BWPM698 and 20SIR700, helping buyers narrow replacement candidates by existing part reference. Its 2-inch pin and 1/2-inch bolster plate add useful dimensional information beyond the model names. The product is engineered for welded installation, creating a permanent connection; included installation hardware is listed, but the welding requirement remains central to the installation workflow.
- Cross-compatible with several named OEM references
- 2-inch kingpin
- 1/2-inch bolster plate
- Engineered for welded installation
- Welded installation creates a permanent connection rather than a bolt-in change.
Skip it if you need a bolt-in replacement or cannot use a welded installation; this kingpin is engineered to be welded in place.
Choose this DETYI option when its listed OEM references and 2-inch pin with 1/2-inch bolster plate align with your trailer. It fits buyers prepared for welded installation, not those seeking a removable bolt-in component.
Full product details
| Brand | DETYI |
|---|---|
| Compatible with Vehicle Type | Trailer |
| Included Components | Installation Hardware |
| Item Weight | 14.8 pounds |
| Manufacturer | DETYI |
| Part Number | 11029298-CR8 |
| Manufacturer Warranty Description | 1 Years Warranty |
| Material | Carbon Steel |
| Model Number | 11029298-CR8 |
Listed on Amazon as: WA15 5050 Fifth Wheel Kingpin 2" & 1/2" Bolster Plate Trailer King Pin
View on Amazon#5
5. ELSOON WA15 5050
- Material: Alloy Steel
- Material Type: Alloy Steel
Best for: WA15 5050 dimension match.
Why it ranks #5: Specifies a forged-steel WA15 5050 replacement with a 2-inch collar and 3/8-inch bolster plate for fifth-wheel trailers.
A 2-inch collar paired with a 3/8-inch bolster plate gives the ELSOON WA15 5050 a clearly specified fit profile for fifth-wheel and gooseneck trailer applications. Forged steel construction supports buyers seeking a heavy-duty towing component, while the stated dimensions help narrow the match before installation.
The forged-steel construction is presented for strength and longevity in harsh, long-term use, making material durability a central part of this option. Its 2-inch collar and 3/8-inch bolster plate provide concrete dimensions for comparing a trailer’s existing king pin, while the listing also identifies fifth-wheel and gooseneck compatibility. That combination helps buyers assess both the intended application and the physical match; the WA15 5050 model designation further identifies the replacement type.
- Forged steel construction
- 2-inch collar
- 3/8-inch bolster plate
- Listed for fifth-wheel and gooseneck trailers
- The listing identifies WA15 5050 compatibility but provides no broader OEM cross-reference numbers.
Skip it if you need a king pin with published OEM cross-reference numbers; this listing names WA15 5050 compatibility only.
This suits buyers matching a WA15 5050-style king pin for fifth-wheel or gooseneck trailer use and wanting forged steel construction. Its listed 2-inch collar and 3/8-inch plate are the fit boundaries to check against the assembly.
Full product details
| Brand | ELSOON |
|---|---|
| Compatible with Vehicle Type | Truck |
| Included Components | 1 x Trailer King Pin |
| Manufacturer | ELSOON |
| Part Number | WA15 5050 |
| Manufacturer Warranty Description | 3 months warranty |
| Material | Alloy Steel |
| Model Number | WA15 5050 |
Listed on Amazon as: WA15 5050 Forged Steel Trailer King Pin with 2" Collar and 3/8" Bolster Plate Compatible with 5th Wheel Trailers for Enhanced Towing Stability and Load Capacity
View on Amazon#6
6. YuShaTra WA15 5050
Best for: Multi-reference WA15 replacement.
Why it ranks #6: Lists a 2-inch collar, 3/8-inch bolster plate, and replacement references for Dayton, Batco, Spicer, Standard, and Mack.
A broad set of named replacement references gives the YuShaTra WA15 5050 kingpin a practical identification advantage for trailer owners checking an existing part. Its 2-inch collar and 3/8-inch bolster plate define the stated dimensions, while high-strength steel construction targets heavy-duty fifth-wheel service.
The listing identifies replacements for Dayton 11 0212, Batco 11 200, Spicer 13101, Standard 20BWPM698 and 20SIR700, and Mack 3889 KPT809F, helping buyers compare the existing part against several named references. A 2-inch collar and 3/8-inch bolster plate specify the key dimensions for that check. High-strength steel is described as durable and wear-resistant for demanding conditions, and the stated stable, secure fit is intended to help prevent accidental decoupling.
- WA15 5050 replacement designation
- Several named Dayton, Batco, Spicer, Standard, and Mack references
- 2-inch collar with 3/8-inch bolster plate
- High-strength steel described as wear-resistant
- No components are listed as included with the kingpin.
Skip it if you need installation hardware supplied; the listing specifies no included components.
This fits buyers comparing a WA15 5050 replacement against the listed Dayton, Batco, Spicer, Standard, or Mack references. Confirm the 2-inch collar and 3/8-inch plate match the assembly, and plan separately for installation components.
Full product details
| Brand | YuShaTra |
|---|---|
| Included Components | no |
| Manufacturer | YuShaTra |
| Part Number | YuShaTra3sm62biyxg |
| Manufacturer Warranty Description | manufacturer warranty for 90 day |
| Model Number | YuShaTra3sm62biyxg |
Listed on Amazon as: WA15 5050 Trailer Kingpin, High Strength Fifth Wheel Kingpin with 2 Inch Collar and 3/8 Inch Bolster Plate, Heavy Duty Steel King Pin for 5th Wheel Trailer Hitch, Replacement
View on Amazon#7
7. Spryflower WA15 5050
Best for: WA15 5050 secure-fit replacement.
Why it ranks #7: Provides WA15 5050 replacement references and a 2-inch collar with 3/8-inch bolster plate, but lists no included components.
The Spryflower WA15 5050 kingpin combines a 2-inch collar with a 3/8-inch bolster plate, giving buyers specific dimensions for a fifth-wheel replacement check. Its high-strength steel construction is described as durable and wear-resistant, while named Dayton, Batco, Spicer, Standard, and Mack references aid part identification.
The WA15 5050 designation and references to Dayton 11 0212, Batco 11 200, Spicer 13101, Standard 20BWPM698 and 20SIR700, and Mack 3889 KPT809F help buyers compare a replacement to an existing part. Its 2-inch collar and 3/8-inch bolster plate specify the stated fit dimensions. High-strength steel is described as wear-resistant for heavy-duty trailers, and the stable, secure design is presented as helping maintain the trailer connection.
- WA15 5050 replacement designation
- Cross-references several named OEM parts
- 2-inch collar and 3/8-inch bolster plate
- High-strength steel described as wear-resistant
- No installation components are listed as included.
Skip it if you need installation components included with the kingpin; this listing specifies none.
This suits trailer owners checking a WA15 5050 replacement against the listed Dayton, Batco, Spicer, Standard, or Mack references. The 2-inch collar and 3/8-inch plate are the key fit considerations, and installation components are not listed as included.
Full product details
| Brand | Spryflower |
|---|---|
| Included Components | no |
| Manufacturer | Spryflower |
| Part Number | Spryflowerxvme5dayu3 |
| Manufacturer Warranty Description | manufacturer warranty for 90 day |
| Model Number | Spryflowerxvme5dayu3 |
Listed on Amazon as: Trailer Kingpin WA15 5050, 5th Wheel Kingpin with 2 Inch Collar and 3/8 Inch Bolster Plate, High Strength Steel Trailer Hitch King Pin, Replacement for Dayton Parts 11 0212, Batco
View on AmazonAvoiding king-pin fitment and installation traps
A matching 2-inch collar alone does not prove that a king pin fits your trailer. These listings pair that dimension with different bolster plates: Buyers Products KP20038 specifies 0.38 inch, Tulga Fifth Wheel THLD2 specifies 0.5 inch, and several WA15 5050 listings specify 3/8 inch. Those values are not interchangeable assumptions; verify the trailer manufacturer’s required dimensions and compare them with the existing part or service information.
Model references can help narrow the search, but DETYI WA15 5050 explicitly advises confirming fitment for the specific trailer. A second trap is treating every listing as equally complete: DETYI lists installation hardware, while YuShaTra and Spryflower list none.
Finally, these are weld-on or welded-installation parts. Incorrect fit, preparation, or welding can compromise the connection, so use a qualified installer and follow the trailer maker’s procedure rather than relying on a product title.
What the steel details do—and do not—tell you
More detailed steel specifications help compare listings, but they do not establish a complete load rating or prove that a pin suits a particular trailer. Buyers Products KP20038 identifies forged AISI 8630 steel, heat treatment to 302–363 BHN, and 150,000 PSI ultimate strength; Mytee Products Kingpin lists 8630 alloy steel and approximately 150,000 PSI ultimate strength. Tulga Fifth Wheel THLD2 identifies forged 4140-quality steel, while other WA15 5050 listings use broader descriptions such as forged steel or high-strength steel.
That difference in detail is useful when deciding what information to seek, not a basis for declaring an unsupported capacity winner. Mytee also says its pins are not for off-road use, an important stated limitation.
Check the complete trailer and hitch requirements, including the exact replacement part reference, before treating material or strength figures as a fitment decision.
How to Choose a Trailer King Pin
Match collar and bolster dimensions
Start by matching both the collar diameter and bolster-plate thickness to the trailer’s specified king pin. Buyers Products KP20038 lists a 2-inch pin and 0.38-inch plate; ELSOON WA15 5050 lists a 2-inch collar and 3/8-inch plate, while Tulga Fifth Wheel THLD2 lists a 2-inch pin and 0.5-inch plate. The 0.38-inch and 3/8-inch descriptions are equivalent fractions, but neither should be substituted for a required 0.5-inch plate.
Buyers whose existing specification calls for a half-inch plate should look closely at Tulga; those with a 3/8-inch specification can compare Buyers Products or the WA15 options. Confirm the required dimensions from the trailer documentation or removed part before buying.
Check exact replacement references
Look for a model or cross-reference that matches the trailer’s existing part, not just a familiar 2-inch size. DETYI WA15 5050 lists compatibility with Dayton 11-0212, Batco 11-200, Spicer 13101, and Standard 20BWPM698 and 20SIR700, while YuShaTra and Spryflower give similar replacement references and also list Mack 3889 KPT809F. ELSOON identifies the WA15 5050 model, and Buyers Products KP20038 gives its own model and dimensions rather than the same cross-reference list.
A buyer replacing a documented WA15 5050 part can start with those referenced options, then verify the exact trailer application. If the existing pin’s identity is unclear, confirm fitment with the trailer maker or a qualified parts supplier before ordering.
Compare material detail and installation notes
Prefer a listing that gives material and installation details relevant to your requirements, while treating broad strength language cautiously. Buyers Products KP20038 specifies forged AISI 8630 steel, heat treatment, 302–363 BHN hardness, and 150,000 PSI ultimate strength; Mytee Products Kingpin lists 8630 alloy steel and magnetic-particle inspection, but states it is not for off-road use. Tulga Fifth Wheel THLD2 specifies forged 4140-quality steel, while some WA15 listings say only high-strength or forged steel.
Mytee may suit a buyer prioritizing stated inspection details and US manufacture, provided the off-road limitation does not conflict with use. Buyers seeking a documented material and hardness range can favor Buyers Products.
All weld-on choices still require appropriate installation; listed steel details do not replace trailer-specific procedures.
Which Trailer King Pin Should You Choose?
Choose Buyers Products KP20038 if your trailer calls for a 2-inch pin with a 0.38-inch bolster plate and you want the listing’s detailed AISI 8630, hardness, and strength specifications. For a specified 0.5-inch plate, Tulga Fifth Wheel THLD2 is the dimension-matched option here, with forged 4140-quality steel. If your replacement is identified as WA15 5050, compare DETYI WA15 5050, ELSOON WA15 5050, YuShaTra WA15 5050, and Spryflower WA15 5050 against the exact part references; DETYI lists installation hardware and several cross-references.
Mytee Products Kingpin suits buyers who value its stated US manufacture and inspection details, but heed its not-for-off-road-use limitation. In every case, verify fit and use qualified weld-on installation.
Related Buying Guides
Frequently Asked Questions
How can I identify the correct king pin and bolster-plate dimensions for my trailer?
Check the trailer or existing part documentation for the required pin and bolster-plate dimensions, then compare those measurements with the product listing. Do not assume that a matching collar diameter is sufficient. If dimensions or part references are unclear, have a qualified trailer professional confirm fit before ordering or installation.
Can I replace a welded trailer king pin myself, or should a shop do the work?
Use a qualified shop unless you have the equipment and experience to follow the trailer maker’s weld-on installation procedure. A king pin is a critical connection, and choosing a dimension-matched part does not confirm that the weld or installation is correct. Verify fit and procedure before any replacement work.
What signs mean a trailer king pin or its welds need inspection or replacement?
Have the king pin and welds inspected if you notice visible cracks, deformation, looseness, or unusual wear around the connection. These signs warrant a professional assessment rather than continued use based on appearance alone. Follow the trailer maker’s inspection guidance, and have any suspected damage evaluated before towing again.
How should I compare WA15 5050 replacement listings?
Compare the exact WA15 5050 part reference and the listed dimensions against your existing part and trailer requirements. Some listings include cross-references or installation hardware, but those details do not establish fit by themselves. DETYI lists installation hardware and several cross-references; confirm compatibility with the trailer before choosing.
What should I verify before choosing a weld-on king pin?
Confirm the required pin and bolster-plate dimensions, the product’s stated material or specifications, and the installation procedure for your trailer. For example, the Buyers Products option is described as weldable and is specified for a 2-inch pin and 0.38-inch plate. Use qualified weld-on installation and verify fit first.
Final Words
Choose by the trailer’s specified pin and bolster-plate dimensions, not by collar size alone. Buyers Products KP20038 is the overall pick when the required dimensions are 2 inches and 0.38 inch and its detailed material specifications matter. For a 0.5-inch plate, consider Tulga; for a WA15 5050 replacement, compare the exact references.
Check limitations, verify fit, and use qualified weld-on installation.
