Standard Trailer Hitch Pin Size
Choosing the right pin for a trailer hitch is a small decision with important safety consequences. The pin keeps the ball mount or hitch-mounted accessory locked inside the receiver tube while the vehicle is moving. Drivers often search for a standard trailer hitch pin size after noticing wobble, rust, or missing hardware on a used hitch. Because receiver openings and pin holes vary by hitch class and manufacturer, the answer is not a single universal measurement. It depends on the receiver tube dimensions, the hole diameter, and the weight demands of the towing setup.
Essential answer
The most common trailer hitch pin has a 5/8-inch diameter and fits the hole drilled through a 2-inch receiver tube. This size dominates light-duty and medium-duty towing, including many Class III and Class IV hitches used on pickups, SUVs, and crossovers. A pin of this diameter passes through the receiver and the ball mount shank, then receives a clip or lock on the opposite side. When drivers ask about a standard trailer hitch pin size, they are usually describing this familiar 5/8-inch component.
The qualification is that receiver openings also come in other sizes, and a 2-inch receiver does not always use the same pin hole. Smaller 1-1/4-inch receivers commonly accept a 1/2-inch pin, while heavier 2-1/2-inch receivers may need a larger pin. Hitch configuration, tongue weight, and gross vehicle weight rating all influence what the manufacturer engineers into the connection. Before purchasing a replacement, the owner should measure the hole in the receiver and the shank rather than assuming the nominal receiver class dictates the pin.
