Choosing a Trailer Hitch Pin at Harbor Freight
Immediate Answer
A Harbor Freight trailer hitch pin is typically a replacement or upgrade pin that secures a ball mount or hitch-mounted accessory inside a receiver tube. The correct pin is one that matches your receiver's inside diameter, usually 5/8 inch for Class III, IV, and V hitches, and 1/2 inch for many Class I and II hitches. The material condition that changes the choice is your exposure to theft or weather: a locking pin adds security but costs more, and stainless steel resists corrosion better than zinc-plated steel.
What a Trailer Hitch Pin Does
The hitch pin passes through the aligned holes in the receiver tube and the shank of the ball mount, drawbar, bike rack, or cargo carrier. A clip or cotter pin then locks into a groove near the end of the pin so the accessory cannot slide out during towing.
Measuring the Correct Diameter
Match the pin diameter to the receiver opening rather than to the accessory alone. A loose pin increases vibration and wear. The common sizes are:
Class I and Class II receivers: often use a 1/2-inch pin; Class III, IV, and V receivers: usually use a 5/8-inch pin; Some heavy-duty or specialty receivers: may require a larger or manufacturer-specific pin
If you do not know your hitch class, measure the inside width of the receiver opening and the hole diameter. The pin should slide through with light hand pressure but without noticeable side play.
Usable Length and Clearance
A pin must be long enough to reach fully across the receiver tube with the accessory shank inserted. An excessively long pin can interfere with nearby components or rattle. Harbor Freight pins are offered in different usable lengths, so check the shank width of your ball mount or accessory before purchase.
Standard Pin Versus Locking Pin
A standard pin uses a simple retaining clip and is easy to remove. A locking pin has an integrated keyed lock and replaces the clip. Choose a locking pin if you leave the ball mount installed in public parking areas or theft-prone locations. The trade-off is that the lock cylinder can seize if not lubricated periodically, especially in road salt or coastal conditions.
Material and Corrosion
Zinc-plated steel is an economical choice for occasional towing and dry climates. Stainless steel adds rust resistance for high-moisture or salt environments. Bent-handle pins are easier to grip with gloves. A locking pin may have a dust cap over the keyhole to protect the mechanism.
Installation Check
Insert the accessory shank fully so its pinhole lines up with the receiver holes. Push the pin through from one side and install the retaining clip or lock on the opposite side. Pull the accessory outward to confirm there is minimal movement. The pin should not be load-bearing in a way that causes bending; its job is retention, not carrying tongue weight.
What to Take to the Store
Know your receiver size, the outside width of the accessory shank, and whether you want a clip or lock. If selecting a lock, consider choosing one with a weather-resistant cap. Inspect the pin for a smooth shank without burrs and a key that operates without sticking before leaving the store.
Unresolved Details
Harbor Freight's in-store selection changes by location and inventory cycle. Exact model numbers, current prices, and real-time availability were not supplied and should not be assumed. Verify the pin diameter against your specific hitch's instruction sheet if the receiver was modified or is from an aftermarket brand with nonstandard hole sizing.