Heavy-Duty Trailer Hitch Locks

Updated October 2026 · How we make money

Our top picks

Best Class III/IV valueMaster Lock 2866DAT

Master Lock 2866DAT

Fits 1/2 and 5/8 in receivers.

About $19 (masterlock.com list)

Check price at Master Lock ↗
Best universal (stainless option)Trimax TS32

Trimax TS32

Fits 1/2 and 5/8 in with sleeve.

Check current price

Check price at Trimax ↗
Best heavy-duty hitch locksAMPLock

AMPLock

Custom-fit range for many coupler types.

Check current price

Check price at AMPLock ↗
Quick answer: For heavy towing, use a 5/8 in locking pin rated for your hitch class: the Master Lock 2866DAT is rated Class III/IV to 10,000 lb; for 2-1/2 in Class V receivers you need a longer span such as the Trimax T5 (3-1/2 in). Protect the trailer itself with a heavy steel coupler lock like Proven or AMPLock.
Illustration of a locking hitch pin through a receiver and ball mount
Illustration of a locking hitch pin through a receiver and ball mount (TrailerLock illustration).

Comparison

LockBest forFitsPrice (approx.)
Master Lock 2866DATBest Class III/IV value1/2 in and 5/8 in receivers; 2-3/4 in usable pin lengthAbout $19 (masterlock.com list)Check price ↗
Trimax TS32Best universal (stainless option)1/2 in and 5/8 in receivers (with sleeve)Check current priceCheck price ↗
AMPLock (coupler, gooseneck, kingpin, hitch, latch pin, door locks)Best heavy-duty hitch locksCoupler (boat, RV, cargo), gooseneck (Bulldog, Atwood), kingpin, hitch 1-1/4 to 3 in, latch pin, barn/roll-up doorCheck current priceCheck price ↗

How we chose: picks are based on published specifications, materials, fit charts, manufacturer information and patterns in owner reports. We have not lab-tested these locks. Prices are approximate list prices seen on maker sites in October 2026 and change often.

Our picks in detail

Master Lock 2866DAT
Best Class III/IV value

Master Lock 2866DAT

Who it is for: Most trucks with 1-1/4 or 2 in receivers.

Pros
  • Fits 1/2 and 5/8 in receivers
  • Rated up to Class III/IV, 10,000 lb (5/8 in)
  • Weather seal and cap
Cons
  • Only protects the hitch, not an unhitched trailer
  • 2-3/4 in span too short for some receivers
Key specs

5/8 in pin rated Class III/IV, 10,000 lb; 1/2 in Class I/II, 3,500 lb.

Check price at Master Lock ↗
Trimax TS32
Best universal (stainless option)

Trimax TS32

Who it is for: Owners with more than one receiver size.

Pros
  • Fits 1/2 and 5/8 in with sleeve
  • Stainless version available
  • Keyed-alike sets
Cons
  • Price not confirmed on our check
Key specs

Trimax T5 pin (5/8 in, 3-1/2 in span) fits Class V hitches.

Check price at Trimax ↗
AMPLock
Best heavy-duty hitch locks

AMPLock (coupler, gooseneck, kingpin, hitch, latch pin, door locks)

Who it is for: Owners who want custom-fit security and a fit-finder.

Pros
  • Custom-fit range for many coupler types
  • 5-year warranty with registration
  • Fit quiz on maker site
Cons
  • Prices not confirmed on our check
  • Heavy
Key specs

5-year warranty with registration (per maker).

Check price at AMPLock ↗

This guide covers one angle

This page is only about Class IV and V receivers, 2-1/2 and 3 in hitches and heavy loads. For the full comparison of every option, see our hub guide: best trailer hitch locks.

Ratings matter

A hitch pin lock is a load-bearing part while you tow. Match or exceed your hitch class and gross trailer weight. Do not use an unrated lock as a towing pin.

Heavy-duty features

Our pick

Master Lock 2866DAT: best class iii/iv value. Most trucks with 1-1/4 or 2 in receivers. If budget matters more, see the other picks above.

Check price at Master Lock ↗

FAQs

What is the strongest hitch lock?
Look for hardened or stainless steel and a rating that exceeds your towing load; heavy-duty brands publish ratings.
Can I tow with a locking hitch pin?
Yes, if it is rated for your hitch class.

Related guides

Best Trailer Hitch LocksLocking Hitch Pins: How to Get the Size RightBest Gooseneck Trailer LocksBest Trailer Locks for 2026, by Lock Type