BOYISEN 5th Wheel King Pin Lock — Solid Steel, Outward Handle & Warning Tag, 74mm ID

BOYISEN 5th Wheel King Pin Lock is a heavy-duty, solid-steel trailer kingpin lock with an outward handle, blossom-style cylinder, and high-visibility warning tag to secure standard-sized king pins.

If you tow an RV, camper, boat trailer or operate a fleet, protecting the king pin is a straightforward step to deter theft and accidental towing. This BOYISEN lock upgrades the usual design by relocating the turn cylinder outward and adding a built-in handle for faster, safer handling. Its blossom-type locking mechanism and thick steel construction reduce the chance of forced entry and resist weathering so the lock remains functional year after year.

How does the outward handle make locking and unlocking easier?

The handle moves the turning action away from cramped spaces and lets you operate the lock without awkward wrist angles. That simple change speeds hitch checks and reduces fumbling in rain or cold.

• Outward-oriented handle gives better leverage and grip.
• Faster placement and removal at the hitching point.
• Cleaner operation with gloved hands or in tight coupler areas.

What anti-theft features does this king pin lock include?

Security comes from several complementary elements: a blossom-style cylinder that resists pick-and-twist attempts, solid-steel body that resists drilling and bending, and a highly visible warning tag that deters opportunistic thieves. Together they increase the time and effort a thief must spend to attack the lock.

• Blossom lock design reduces exposure of the cylinder to forced tools.
• Drill-resistant, solid steel body adds structural strength.
• Warning tag alerts bystanders and reminds users to remove the lock before hitching.

Will this fit my trailer’s king pin and how big is it?

BOYISEN designed this lock for standard-size king pins; check the lock’s inner diameter against your king pin dimension before purchase. The lock dimensions give a clear guide for compatibility and installation.

• Height: 93.5 mm (clearance for vertical fit).
• Inner diameter: 74 mm — measure your king pin receiver opening first.
• External diameter: 150 mm — overall footprint for storage and fit checks.

What comes in the box and how is key replacement handled?

The package ships ready to use with the lock and keys, plus clear instructions for noting key ID for future copies. If keys are ever lost, the key ID system introduced in recent batches helps expedite replacement copies when you contact BOYISEN.

• Includes: 1 king pin lock and 2 keys for daily use and backup.
• Key ID printed on keys for quick replacement ordering (note it down or photograph it).
• Durable finish protects against corrosion to keep the mechanism working.

Who is this for: Operators who need a rugged, user-friendly king pin lock — trucking fleets, RV owners, boat haulers and commercial haulers who want a visible, heavy-duty deterrent that’s simple to use. Choose this BOYISEN model when you want an engineered upgrade over basic locks: easier handling, reinforced cylinder protection and a strong steel body designed to hold up under heavy use and outdoor exposure.