Identify CURT Trailer Coupler Safety Pins by Size and Retainer
When the original trailer-coupler pin has been lost, the quickest identification clues are its actual shaft diameter, straight pin length and the presence of a tether chain. CURT uses several part numbers for the same diameter because chained and packaged versions are sold separately. This guide helps distinguish them without confusing them with hitch-receiver pins.
Recognize the pin family
1/4-inch pins · 2-3/4-inch length
25080 is the basic pin. 25012 adds a 12-inch tether chain; 25013 is the packaged chained model. They all use a square wire retaining clip.
5/16-inch pins · 3-inch length
25010 and packaged 25011 have no tether. 25034 and packaged 25035 include the 12-inch chain. Check that the larger shaft fits the original latch hole.
3/8-inch pin · 2-3/4-inch length
28278 is the unchained 3/8-inch-diameter option in this comparison. It is not a substitute for a 1/4- or 5/16-inch hole without manufacturer approval.
Do not confuse pin roles
These are small, straight safety pins for appropriate coupler latches, jack legs and similar components. A hitch-receiver pin secures a ball mount or receiver accessory and is selected separately.
CURT safety pin size and model chart
| CURT MPN | Diameter | Pin length | Tether chain | Version |
|---|---|---|---|---|
| 25080 | 1/4 in | 2-3/4 in | No | Unchained pin |
| 25012 | 1/4 in | 2-3/4 in | 12 in | Chained version |
| 25013 | 1/4 in | 2-3/4 in | 12 in | Packaged chained version |
| 25010 | 5/16 in | 3 in | No | Unchained pin |
| 25011 | 5/16 in | 3 in | No | Packaged unchained version |
| 25034 | 5/16 in | 3 in | 12 in | Chained version |
| 25035 | 5/16 in | 3 in | 12 in | Packaged chained version |
| 28278 | 3/8 in | 2-3/4 in | No | Unchained pin |
A coupler safety pin must fit the original attachment hole and engage its retainer. The optional tether chain does not replace proper coupler latching or trailer safety chains.
Inspect the original or replacement pin
- Measure the pin diameter and its straight working length rather than relying on a trailer brand or receiver size.
- Verify that the square retaining wire is present, undamaged and able to close fully around the pin.
- If a chained assembly is present, inspect the attachment chain separately; a missing chain does not justify substituting a different diameter.
- Check whether the original is a packaged model or the corresponding loose-number variant, then compare the individual listing's contents.
- Do not use a bent, heavily worn or visibly corroded pin. Check the coupler's closing and locking mechanism before towing. UsedRVParts product viewing and pickup in Kelowna are by appointment.
Find the matching CURT retaining pin
Check each item's photographs, condition and supplied parts before selecting a replacement.
Other towing safety parts
For the secondary connection between the trailer frame and tow vehicle, compare CURT safety-chain and cable assemblies. A coupler latch pin is not a trailer safety chain or cable.
To secure a ball mount to a hitch receiver, use our separate CURT hitch-receiver pin and lock guide.
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