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Last updated: September 2026
A hitch lock helps stop thieves from walking off with your ball mount, bike rack or cargo carrier, or hooking up your trailer and driving away with it. There are two main types: a receiver lock (a locking pin that replaces your hitch pin) and a coupler lock (which blocks the trailer’s coupler so it can’t be hitched). This guide compares seven options from Master Lock, CURT, TowWorks, Trimax and Proven Industries.
How we chose: this is a comparison based on Amazon listing titles, brand and stated fit, not hands-on testing. No lock is theft-proof. A good lock slows a thief down and makes your gear a less attractive target.
Quick Picks: Best Hitch Locks
- Receiver lock, Class III/IV: Master Lock 1479DAT barbell receiver lock (5/8″)
- Curved receiver lock: Master Lock 2866 receiver hitch lock
- Keyed-alike receiver lock: CURT 23021-KA (5/8″ pin)
- For 3″ receivers and adjustable channel mounts: TowWorks 79831 extra-long span
- Coupler + receiver combo: Trimax UMAX100 with chrome receiver lock
- Heavy-duty coupler lock: Proven Industries Model 2516 (2-5/16″ couplers)
- Keyed-alike coupler locks, 2-pack: Master Lock 2KA-377-37
Hitch Lock Comparison
| Lock | Type | Fit (per listing) |
|---|---|---|
| Master Lock 1479DAT | Barbell receiver lock | 5/8″ pin, Class III/IV |
| Master Lock 2866 | Curved receiver lock | See listing |
| CURT 23021-KA | Receiver lock, keyed alike | 5/8″ pin; 2″, 2-1/2″ or 3″ receiver |
| TowWorks 79831 | Receiver lock, 4-1/2″ span | 5/8″; 3″ receivers and adjustable channel mounts |
| Trimax UMAX100 | Coupler lock + receiver lock | Universal coupler lock (see listing) |
| Proven Industries 2516 | Coupler lock | 2-5/16″ couplers |
| Master Lock 2KA-377-37 | Coupler/tongue locks, 2-pack | See listing |
Best Receiver Hitch Locks
These replace your standard hitch pin so the ball mount, bike rack or cargo carrier can’t be pulled out of the receiver.
1. Master Lock 1479DAT Barbell Receiver Lock
Bottom line: A barbell-style receiver lock with a 5/8″ (16mm) pin, listed for Class III and IV hitches. Master Lock is one of the best-known lock brands.
What to know: Measure your receiver’s pin hole. Class I and II hitches usually use a 1/2″ pin.
2. Master Lock 2866 Curved Receiver Lock
- Swivel Head allows for access to keyway in tight spots.
- No key required to lock – featuring the new Push to Lock Technology.
- Chrome plated for improved wear and corrosion resistance. Solid brass lock cylinder and cylinder case offer extreme corr…
Bottom line: A curved receiver hitch lock from Master Lock. Verify it clears your hitch and any accessory before ordering.
What to know: Check the pin diameter and receiver size on the listing before ordering.
3. CURT 23021-KA Keyed-Alike Receiver Lock
- DEPENDABLE SECURITY — To protect your trailer and trailer hitch ball mount from theft, this locking hitch pin is made wi…
- EASY TO OPERATE — This deadbolt-style locking hitch pin has a heavy-duty look to deter theft, and uses a simple 1/4-turn…
- VERSATILE — With a 5/8-inch diameter pin, this receiver hitch lock fits virtually any 2-inch, 2-1/2-inch or 3-inch hitch…
Bottom line: A 5/8″ locking hitch pin that fits 2″, 2-1/2″ or 3″ receivers, keyed alike. If you want several locks to share one key, confirm they have the same key code before ordering.
4. TowWorks 79831 Extra-Long Receiver Lock
- EXTRA LONG PIN FITS MOST ADJUSTABLE HITCHES – Extra long 5/8″ diameter locking hitch pin with maximum active length 4-1/…
- SPRING CLIP (COTTER PIN) PROVIDES ADDITIONAL SAFETY – A separate spring clip (cotter pin) provides additional safety, ca…
- RUBBER O RINGS KEEP RATTLES DOWN – Rubber O rings prevent any rattling and hold the hitch pin still. * Different brand h…
Bottom line: A keyed 5/8″ hitch lock with an extra-long 4-1/2″ span, listed for 3″ receivers and adjustable channel mounts, where a standard pin is too short.
What to know: Only choose the long span if you need it. On a standard 2″ receiver, a normal-length pin fits more snugly.
Best Trailer Coupler Locks
These lock onto the trailer’s coupler so nobody can drop it onto their own hitch ball.
5. Trimax UMAX100 Coupler Lock with Receiver Lock
Bottom line: A universal solid hardened-steel trailer lock listed with a coupler lock and a chrome receiver lock, so you can secure the trailer when it’s parked and the hitch when you’re towing.
What to know: “Universal” coupler locks fit many couplers, but check the listing’s fit details against your trailer.
6. Proven Industries Model 2516 Coupler Lock
- HEAVY-DUTY TRAILER LOCK: It’s important to do everything you can to protect your belongings and your trailer or camper f…
- TOUGH LOCK: The locking parts on this device are constructed from hardened steel for increased security, and the exterio…
- UNIQUE KEY DESIGN: Our trailer lock has a special key design that prevents anyone from picking the lock. This innovative…
Bottom line: A heavy-duty trailer coupler lock for 2-5/16″ couplers, listed as made in the USA. Proven Industries is known for its heavy-duty trailer locks.
What to know: It’s made for 2-5/16″ couplers, so check your trailer’s coupler size.
7. Master Lock 2KA-377-37 Coupler Locks (2-Pack, Keyed Alike)
- Complete security for your trailer’s coupler/tongue. These locks will fit virtually all trailers that have 1-7/8″ or 2″ …
- KEYED ALIKE – One key opens all three locks. We can key multiple sets to the same key number. If multiples are ordered w…
- COUPLER LOCK FEATURES: Advanced locking mechanism resists picking and prying. Simple installation and removal. Aluminum …
Bottom line: Two keyed-alike trailer coupler and tongue locks from Master Lock, useful if you have more than one trailer.
Who a Hitch Lock Is NOT For
- Anyone expecting a lock to stop a determined thief: locks deter and delay. Park in a secure, well-lit place and consider a wheel lock for a parked trailer too.
- Buyers who haven’t measured their pin hole or coupler: the wrong size simply won’t fit.
How to Choose a Hitch Lock
Receiver lock or coupler lock?
If you leave a bike rack, ball mount or cargo carrier in your hitch, get a receiver lock. If you park a trailer, get a coupler lock. Many owners use both.
Measure first
For receiver locks, check the pin diameter (1/2″ or 5/8″) and receiver size. For coupler locks, check the coupler ball size (1-7/8″, 2″ or 2-5/16″).
Weather resistance
Hitch locks live outside. Look for dust caps or covers over the keyway, and lubricate the lock before winter.
Keyed alike
Keyed-alike sets let one key open all your locks, which is handy when you have a bike rack, trailer and cargo carrier.
Frequently Asked Questions
What size hitch lock do I need?
Most Class III and IV hitches with a 2″ receiver use a 5/8″ pin. Class I and II hitches with a 1-1/4″ receiver usually use 1/2″.
Do I need a hitch lock for a bike rack?
If you leave the rack on your vehicle, a locking hitch pin helps stop someone from pulling it out of the receiver.
What’s the difference between a hitch lock and a coupler lock?
A hitch (receiver) lock secures whatever is in your receiver. A coupler lock secures a parked trailer’s coupler.
Are keyed-alike locks less secure?
Not really. They share one key design, which is a convenience. Keep your spare key safe.
How do I stop my hitch lock from seizing?
Keep the dust cap on and use a lock lubricant, especially before winter.
Setting up your hitch? See our best trailer hitch, hitch bike rack and hitch cargo carrier guides.
Final Thoughts
For most 2″ receivers, a Master Lock 1479DAT or CURT 23021-KA locking pin is the simple choice, and TowWorks covers 3″ receivers. For parked trailers, a Proven Industries or Trimax coupler lock adds serious deterrence. Measure your pin hole and coupler size before you order.
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