Master Lock Trailer Coupler Lock Coupler Lock, 3.5in shackle 9/32in pin, weather-resistant brass with water-tight cap

The Master Lock 1471DAT is a weather-resistant trailer coupler latch lock with a 3.5" long shackle and 9/32" diameter pin designed to stop unauthorized tow-away and keep your trailer coupler secured.

Whether your trailer is hitched to a vehicle or parked unattended, the 1471DAT locks the coupler latch to prevent the ball from being inserted or removed. Built from solid brass with chrome plating, this latch lock combines corrosion resistance with long-term durability. Its 4-pin tumbler mechanism offers reliable pick resistance while a water-tight cap and weather seal protect internal parts from moisture and dirt.

How does this lock prevent trailer theft and accidental uncoupling?

The Master Lock 1471DAT physically blocks the coupler latch movement so the coupler cannot be opened or closed. That means thieves cannot mount a ball to tow your trailer, nor can the coupler be removed when improperly accessed. The lock works whether the trailer is attached or unattached.

• Shackle spans 3.5" to fit standard coupler latch openings
• 9/32" diameter pin fits the common coupler holes on most UFP and surge brake couplers
• Prevents both insertion and removal of hitch ball
• Solid construction deters casual tampering and opportunistic theft

What materials and features make it suitable for outdoor use?

This lock is made from solid brass and chrome-plated to resist wear and corrosion in outdoor environments. A water-tight protective cap and weather-tough seal keep moisture and debris away from the keyway and internal tumblers, extending functional life.

• Solid brass body for durability and corrosion resistance
• Chrome-plated finish to reduce surface wear and rust
• Water-tight cap over the keyway prevents water ingress
• Weather-tough seal protects the 4-pin tumbler mechanism from elements

Will it fit my trailer coupler and how does the locking mechanism perform?

The 1471DAT is manufactured to fit the standard coupler latch dimensions used across most trailers. It uses a precision 4-pin tumbler mechanism that resists picking and provides consistent key operation. Master Lock specifies the pin diameter and shackle span to match typical UFP and surge brake couplers.

• Pin length: 3.4" (3-4/10") to match common latch openings
• Pin diameter: 9/32", the standard size for most couplers
• Precision 4-pin tumbler for reliable security and smooth key action
• Compatible with K1 key blank system

Who is this for: The Master Lock 1471DAT is ideal for trailer owners, contractors, landscapers, or recreational users who need a straightforward, weather-resistant coupler lock to prevent theft and accidental uncoupling. Choose this model if your trailer uses a standard UFP or surge brake coupler and you want a solid brass, chrome-plated lock with a water-tight cap and a reliable 4-pin tumbler mechanism for everyday outdoor use.