Underbody Aluminum Boxes
Alum-Line's Underbody Aluminum Boxes are designed for secure, storage under trucks, trailers, or flatbeds. These boxes are ideal for storing tools, equipment, or gear while maintaining a clean and organized vehicle without wasted, unusable space. Many standard sizes available and can also be built to fit your exact space.
Lightweight Strength That Outperforms Steel
High-strength aluminum delivers durability without unnecessary weight.
Proudly Made in the USA Since 1986
American-built trailers and work products trusted nationwide.
Designed for Commercial & Recreational Use
Built to handle demanding jobs, daily hauling, and custom applications.
Standard Features
Standard features engineered for strength, longevity, and everyday reliability.
- .100" aircraft grade diamond plate aluminum construction (.125 smooth aluminum is the same price)
- Interlocking lid/door with rubber gasket
- Drop down doors with cable stops (side swing available at same cost)
- Key-lock recessed stainless steel T-handle latches (2 latches on boxes 4' and longer)
- Stainless steel strap hinges (bottom) and continuous aluminum piano hinges on upper compartment
- All seams continuous pulse welded
Optional Features
Optional enhancements designed to tailor your build for specific jobs, loads, and real-world use cases.
- Top opening lid
- Step in front 6" width
- Gas shocks
- Mounting brackets 16" and under
- Mounting brackets 18" and over
- Key cylinder protector covers
- Drip rail
- Slam latch or small D-ring latch/paddle
- Double doors (with post or overlap)
- RV notch on sides
- SS piano hinges
- Mirror SS (polished doors)
- (3) point latch
- T handles
- Brushed SS
- Black compression latch
- Tapered angles on box
- Slider under 34"; up to 270 lbs (per pair) ACC3600
- Slider under 60" up to 500 lbs (per pair) ACC9301
- Tray with 2" lip
- Solid shelving
- Adjustable shelving (larger boxes only)
- Divider
- Extra door
Popular Sizes
See Our Products in Action
Get a closer look at the design, construction, and real-world performance behind every Alum-Line build.
Decades of experience, trusted by thousands—precision, strength, and reliability in every build.
American-built aluminum products designed for real-world work, backed by three core principles for every product delivered
Built on 40 Years of Proven Craftsmanship
Since 1986, Alum-Line has produced premium all-aluminum trailers, truck beds, bodies, boxes, and specialty transport solutions for customers across the U.S. Our decades of experience shape every weld, panel, and design we build.
USa Manufacturing Power That Sets Us Apart
With over 120,000 sq. ft. of production space, dedicated plants, and continuous expansion, Alum-Line delivers the strength, precision, and consistency needed for commercial-grade performance in every product.
Nationwide Network Backed for years
Supported by 200+ dealers across the country and protected by a five-year workmanship warranty, our aluminum solutions are engineered to outperform steel and built to last a lifetime.
Trailers Built For Hard Work Across America.
With years of hands-on experience and a commitment to quality craftsmanship, we turn raw materials into real-world solutions — from custom industrial parts to full-scale fabrication projects.
Years in Business
120,000 Sqft Manufacturing Facilities
Dealers Across the USA
Where Workmanship Lasts a Lifetime.
Specials
Limited-run pricing on select aluminum builds—grab deals before they’re gone.
New Products
Newly engineered additions built for tougher jobs and higher performance.
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Warranty
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