Begin RV

Trailer Hitch (tow hitch)

What Is a Trailer Hitch? 

A trailer hitch is the primary connector between the tow vehicle (a car, van, pickup truck or SUV) and the trailer being towed. It is the specialized component that bolts onto the towing vehicle and provides a connection point to hook up the trailer being towed. 

The ball mount (pictured on the right side of the picture below) is commonly mistaken as the trailer hitch. While the ball mount is one of the trailer hitch parts, it is not technically the hitch

Trailer Hitch
Trailer hitch and ball mount


  • Primary connector between the tow vehicle and the trailer being towed.
  • Rated in 5 classes (Class I-V) designating the hitch opening size and weight capacity.
  • Made up of several components including receiver, ball mount, trailer ball and coupler.


Understanding the Trailer Hitch

A trailer hitch is specialized hardware which attaches directly to a tow vehicle. It provides the connection between the tow vehicle and the trailer to allow for safe towing of a trailer. Hitch installations are most often permanently attached to the tow vehicle. 

Trailer hitches have “receivers” which is the receptacle part of a trailer hitch accommodating inserts such as ball mounts, drawbars or accessory carriers.  

There two major factors in understanding the trailer hitch: 

  1. Trailer Hitch Components 
  2. Hitch Classes

I.  Trailer Hitch Components

There are a number of components that make up the trailer hitch system: 

Trailer Hitch Diagram
Diagram courtesy of Curt


Tow Vehicle

The tow vehicle is any car, truck, SUV or other automotive vehicle responsible for towing the trailer. Each  vehicle has different towing capacity. The lowest-rated towing component — including the tow vehicle itself — will limit the maximum amount of weight you can tow.

Pickup Truck Towing Travel Trailer

Hitch Receiver

The  rearward-facing opening on the hitch that accepts removable ball mounts, hitch bike racks, cargo carriers, or other hitch-mounted accessories.

Ball Mount (or ball hitch)

A ball mount is a receiver hitch accessory comprised of a shank and a trailer ball platform. The shank inserts into the hitch receiver tube, while the platform provides a solid mounting point for a trailer ball. [1]

Ball Mount Hitch

Nearly all ball mounts come with a hole in the shank to accept a hitch pin or hitch lock.

Hitch Ball

The ball-shaped attachment to a hitch onto which a trailer coupler is attached. 

Hitch Pin

A hitch pin is the metal rod-like accessory that prevents a ball mount and other trailer hitch parts from sliding out of the receiver. [2]See above The hitch pin is designed to slide into the side of the hitch receiver, pass through the ball mount shank and come out the other side.  Hitch pins have a hole on the end to accept a hairpin-shaped clip for additional security. 

Trailer Coupler

A trailer coupler together with the trailer ball physically connects a trailer to your vehicle. The trailer coupler latches onto the trailer ball and form a secure joint for smooth towing. In order for safe operation, the size of the trailer coupler must match the size of the trailer ball. 

Safety Chains

The safety chains are the chain(s) that connect from the trailer tongue to the tow vehicle. Safety chains keeps the trailer from completely separating from the tow vehicle if it ever becomes disconnected while towing. 

Trailer Chains

Two safety chains are required and must be attached to their own chain retainers.

Safety Cable

The safety cable connects the braking system on the trailer to the receiving hitch on your tow vehicle. When the safety cable separates, the trailer’s brakes will automatically engage to prevent a runaway trailer situation on the highway.  

II.  Hitch Classes

Most hitches are made vehicle-specific, allowing the owner to use year, make, model and style to identify the exact hitch needed.  The hitch class and receiver size depends on two factors: (1) what the driver wants to tow, and (2) what the vehicle can handle.  Some vehicles may have more than one hitch option to choose from. 

Trailer hitches are technically  grouped into 4 classes by the Society of Automotive Engineers, however manufacturers have added a fifth class (Class 5) for heavy-duty loads. [3]

Class I has the lowest capacity and Class V having the highest. Hitch classes essentially designate the hitch opening size and weight capacity.

Below is a breakdown of the 5 hitch classes: 

Hitch Class*GTW (Gross Trailer Weight)Receiver SizeSample Cargo
Class IUp to 2,000lbs1-1/4″Kayaks, Jetskis, Bikes, Canoes, Small Scooters
Class IIUp to 3,500lbs1-1/4″Small Trailers, Small Pop-up Campers, Small Boats
Class IIIUp to 5,000lbs2″Midsize Campers, Utility Trailers, Motorcycles, Snowmobiles
Class IVUp to 10,000lbs2″Large Campers, Large Boats, Toy Haulers, Horse Trailers
Class VUp to 17,000lbs2″, 2 1/2″, 3″Fifth Wheels, Multi-car trailers, Horse Trailers
*The GTR (Gross Trailer Weight) is the full loaded trailer weight. It includes the weight of the trailer itself
along with any cargo, passengers, animals, equipment, fluids, etc.


Related RV Terms

For related RV terminology, please reference the RV definitions below:

  • GTW (Gross Trailer Weight): The fully loaded weight of a trailer. It includes the weight of the trailer itself plus any weight added to the trailer (people, fuel, firewood, other vehicles, etc.).

  • GVWR (Gross Vehicle Weight Rating): The maximum loaded weight of a car vehicle that has been determined to be safe by the manufacturer. It encompasses the weight of the passengers, cargo, and the weight of the vehicle itself.

  • Travel Trailer: A non-motorized compact home on wheels that you can tow behind your personal vehicle

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