Tow hitch

A tow hitch (or tow bar) is a device attached to the chassis of a vehicle for towing, or a towbar to an aircraft nose gear. It can take the form of a tow ball to allow swiveling and articulation of a trailer, or a tow pin, or a tow hook with a trailer loop, often used for large or agricultural vehicles where slack in the pivot pin allows similar movements. Another category is the towing pintle used on military vehicles worldwide.

In North America the vehicle attachment is known as the trailer hitch. Trailer hitches come in two main configurations: receiver type and fixed-drawbar type. Receiver-type hitches consist of a portion that mounts to the frame of the vehicle that has a rearward-facing opening that accepts removable ball mounts, hitch bike racks, cargo carriers, or other hitch mounted accessories. Fixed-drawbar hitches are typically built as one piece, have an integrated hole for the trailer ball, and are generally not compatible with aftermarket hitch accessories.

A trailer hitch typically bolts to the chassis of the vehicle. In North America there are a few common classes (I, II, III and IV) that are defined by the Society of Automotive Engineers (SAE). Some manufacturers market Class V hitches, but there is no such standard according to SAE J684.

The trailer tongue (North America) or coupling (outside North America) slips over a tow ball attached to or integral with the hitch.

Receiver tubes come in various sizes depending on the load they carry and the country of operation.

Tow balls come in various sizes depending on the load they carry and the country of operation:

In North America, the ball attaches to a ballmount. Receiver-type hitches use removable ball mounts, whereas the fixed drawbar type hitches have integrated ball mounts. The ball mount must match the SAE hitch class. The ballmount for a receiver-type hitch is a square bar that fits into a receiver attached to the vehicle. Removable ball mounts are offered with varying rise or drop to accommodate variations in the height of the vehicle and trailer to provide for level towing.

In order to tow safely the correct combination of vehicle and trailer must be combined with correct loading horizontally and vertically on the tow ball. Advice should be taken (see references) to avoid problems.

Outside North America, the vehicle mounting for the tow ball is called the tow bracket. The mounting points for all recent passenger vehicles are defined by the vehicle manufacturer and the tow-bracket manufacturer must use these mount points and prove the efficacy of their bracket for each vehicle by a full rig-based fatigue test.

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