Trailer Hasp Bolt Kit — 5/16"-18 Dome Head Bolts with Barrel Nuts for Cam Bar Locks, Hasps & Door Hardware

This Trailer Hasp Bolt Kit contains everything you need to mount or replace the fasteners on your trailer's cam bar locks, door hasps, swing hinges, and door handles. Each kit includes four 5/16"-18 dome head bolts and four matching 5/16"-18 barrel nuts (cross dowel nuts) — the exact hardware used on factory-installed cam bar locking systems on enclosed cargo, horse, utility, and toy hauler trailers.

Available in three bolt lengths — 1-1/2", 2", and 2-1/2" — to fit standard, thick, and extra-thick door panel applications. Select your length from the dropdown above.

The dome head design keeps bolt heads flush and snag-free on the interior of your trailer, protecting your cargo and equipment from catching on exposed hardware. Stainless steel construction resists rust and corrosion for lasting performance even in outdoor and wet conditions.

📏 Available Sizes

🔧 Key Features

• Dome head design — smooth, rounded bolt head sits flush against trailer interior panels; no sharp protrusions to catch cargo, straps, or equipment
• Stainless steel construction — resists rust, corrosion, and oxidation for long-term performance in outdoor and wet environments
• 5/16"-18 coarse thread — the industry-standard thread spec for trailer cam bar locks, hasps, and door hardware
• Barrel nut (cross dowel nut) included — designed to seat inside the trailer wall or hasp body for a secure, rattle-free connection
• Three bolt lengths available — 1-1/2", 2", and 2-1/2" to fit standard through extra-thick door panel applications
• Quick installation — tighten with a standard 7/32" hex / Allen wrench; no special tools required
• 4-piece kit — enough hardware to replace all fasteners on one cam bar lock or hasp assembly

📐 Specifications

What Is This Hardware Used For?

These bolts and barrel nuts are the factory-standard fasteners used to mount cam bar locks, hasps, and door handles on enclosed trailers. The dome head bolt passes through the hasp or cam bar mounting bracket from the outside, and the barrel nut threads onto it from the inside of the trailer wall — drawing the assembly tight against the door panel without requiring access to a nut on the outside.

Common uses include:

• Replacing stripped, rusted, or missing cam bar lock mounting bolts
• Installing a new cam bar lock or hasp assembly
• Securing door handles, hinges, and interior mounting hardware
• Replacing hardware on trailer ramp door bar latches
• Mounting camtainer and cam action hasp assemblies

📏 Choosing the Right Bolt Length

Measure the total thickness your bolt needs to span: the exterior hasp or cam bar bracket, the door panel, and any interior reinforcement. Add about 1/4" for barrel nut seating depth.

• 1-1/2" — most standard enclosed cargo trailer doors (plywood core between aluminum skins, typical 1-1/8" to 1-1/4" door panel)
• 2" — insulated trailers, refrigerated trailers, thicker reinforced doors, and applications where the hasp mounting plate stacks additional material
• 2-1/2" — heavy-duty commercial trailers, extra-thick insulated panels, or multi-layer reinforcement behind the hasp

Compatible Applications

Compatible Trailer Brands & Types

This bolt kit is compatible with the standard 5/16"-18 cam bar and hasp hardware used on trailers from: Haulmark, Pace American, Wells Cargo, Cargo Mate, Continental Cargo, Featherlite, Sundowner, Exiss, Sooner, Logan Coach, Homesteader, Forest River, and most other major enclosed cargo, horse, livestock, and toy hauler trailer brands using standard cam bar lock door hardware.

Trailer types: Enclosed cargo trailers, horse and livestock trailers, toy hauler trailers, van trailers, motorcycle trailers, utility trailers with enclosed doors, and cargo vans with cam bar locking systems.

📦 What's Included (per kit)

💡 Pro Tips

Installation requires only a 7/32" hex / Allen wrench:

• Insert the dome head bolt through the mounting hole in the cam bar, hasp, or door handle bracket from the outside
• Thread the barrel nut onto the bolt from inside the trailer wall or panel
• Tighten with a 7/32" Allen wrench until the assembly is snug against the panel
• Do not overtighten — snug is sufficient to prevent movement and rattling

How many bolts come in the kit?
Each kit includes 4 dome head bolts and 4 barrel nuts — 8 pieces total. This is enough to fully replace the mounting hardware on one standard cam bar lock or hasp assembly. Order multiple kits if replacing hardware on multiple door assemblies.

What wrench size do I need?
A 7/32" hex / Allen wrench fits the barrel nut. No wrench is needed for the dome head bolt — it is held in place by the dome head seating against the bracket.

Will this fit my Haulmark or Pace American trailer?
Yes — these are the industry-standard 5/16"-18 fasteners used on virtually all major enclosed trailer brands. Verify your existing hardware uses 5/16"-18 thread before ordering.

Which length do I need?
Most standard enclosed cargo trailer doors use 1-1/2". Insulated or thick-panel applications often need 2". Extra-heavy commercial or multi-layer mounting typically needs 2-1/2". Call or text us at 517-225-1991 if you're not sure — we'll help you measure.

Can I use these on the exterior of my trailer?
Yes. The stainless steel construction is corrosion resistant and suitable for both interior and exterior trailer applications.

Questions? Call or text AAA Trailer at 517-225-1991 — we stock a full range of trailer door hardware and can help you find exactly what you need. Same-day shipping from Howell, Michigan.

📞 Call/Text: 517-225-1991   🌐 AAATrailer.com

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• Address: 4675 East Grand River Ave, Howell, MI 48843
• Phone: (517) 225-1991 (Call or text)
• Hours: Monday to Friday: 10:00 AM - 5:30 PM | Saturday: By appointment

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