Best Underbody Tool Box For Flatbed: 10 Options Compared

#1 · Best Overall

1. Mytee Products Aluminum Kit

• Dimensions: 20"L x 20"W x 20"H
• Weight: 130 lb
• Material: Aluminum
• Material Type: Aluminum

Best for: Long flatbed trailer storage.

Why it ranks #1: The 24 x 24 x 60-inch aluminum box is explicitly for flatbed trailers and includes two weld-on brackets plus a double-door paddle lock.

A 60-inch aluminum enclosure arrives with two weld-on mounting brackets, giving flatbed trailer owners a matched box-and-bracket kit. The double barn doors use a paddle lock, and the 24-by-24-by-60-inch body provides a long storage bay for tools and equipment carried beneath the trailer.

The aluminum body measures 24 inches high by 24 inches deep by 60 inches long, creating a long compartment for trailer tools and equipment. Its 3 mm, or 11-gauge, body and doors give the enclosure substantial material thickness, while the double barn-door layout provides access across the front. A paddle lock secures the doors, and the kit includes two 24-by-24-inch weld-on brackets sized for this box, so the buyer receives the specified mounting hardware with the enclosure.

Skip it if you cannot weld mounting brackets; VEVOR's 36-inch aluminum box is a smaller alternative without listed weld-on brackets.

This kit fits flatbed trailer owners seeking a long aluminum underbody compartment with matching weld-on brackets and double-door access. Its installation depends on welding those brackets, so it is not the straightforward choice for buyers avoiding welded mounting.

Listed on Amazon as: Mytee Products Heavy Duty Underbody Tool Box Kit – Includes 24"x24"x60" Aluminum Side Mount Tool Box w/Barndoor Double Doors & Paddle Lock & 24"x24" Weld-On Brackets for Flatbed Trailers

#2 · Heavy-Duty Steel

2. Buyers Products 1702305

• Dimensions: 36"L x 18"W x 18"H
• Weight: 76 lb
• Material: Alloy Steel
• Material Type: Alloy Steel

Best for: Large steel flatbed storage.

Why it ranks #2: Its 36 x 18 x 18-inch box uses 14-gauge steel and a locking stainless compression latch, with flatbed use stated in the product details.

A 36-by-18-by-18-inch body and 14-gauge steel construction give this Buyers Products box substantial room for tools and supplies beneath a work truck or flatbed. Its recessed drop door uses a stainless steel compression latch, helping keep contents secured and the door drawn against its gasket during travel.

The 36-inch length and 3,401.64-cubic-inch capacity provide useful space for tools, parts, and supplies, while the 14-gauge steel body suits demanding truck and trailer storage. A recessed drop door pairs with a stainless steel locking T-handle compression latch; the latch pulls the door against its gasket to help limit rattling and weather exposure. The continuous hinge supports the door, and included keys give buyers a lockable storage option for equipment carried under the vehicle.

Skip it if you need a lighter aluminum enclosure; EASYBERG's 36-inch aluminum box weighs 40.1 pounds.

This suits flatbed and work-truck owners needing roomy, lockable steel storage for tools and supplies. Allow for its 76-pound handling weight during installation, and consider whether the 36-by-18-by-18-inch body fits the available underbody space.

Listed on Amazon as: Buyers Products 1702305 36 x 18 x 18 Inch Steel Underbody Tool Box

#3 · Compact Steel

3. Buyers Products 1703100

• Dimensions: 24"L x 16"W x 14"H
• Weight: 45.4 lb
• Material: Alloy Steel
• Material Type: Alloy Steel

Best for: Compact paddle-latch storage.

Why it ranks #3: This 24 x 16 x 14-inch steel box is listed for flatbed and service body trucks and has a recessed drop door with a locking paddle latch.

A locking paddle latch and recessed drop door give this 24-by-16-by-14-inch Buyers Products box a secure, compact format for flatbed and service-body storage. Its 14-gauge carbon-steel body has a black powder-coated finish, while the continuous hidden hinge helps reduce the door's exposure to prying.

The 24-inch length and 24-liter capacity make this a smaller storage choice for tools and supplies, and the listed maximum weight recommendation is 100 pounds. Its 14-gauge carbon-steel body and powder-coated finish provide a durable, corrosion-resistant exterior for work-truck use. The recessed door works with a locking paddle latch, while the continuous hidden hinge reduces exposure to prying; together, these features offer a contained, lockable place for gear carried beneath a flatbed or service body.

Skip it if you store long or bulky gear; Mytee Products' 60-inch double-door box offers a longer enclosure.

Choose this Buyers Products box for a service body or flatbed where a compact, lockable enclosure is more useful than a long chest. Its 24-liter capacity and 100-pound maximum recommendation set a clear limit for bulky or heavy loads.

Listed on Amazon as: Buyers Products 1703100 14x16x24 Inch Black Steel Underbody Truck Box, Locking Paddle Latch, Recessed Drop Door, Weatherproof Tool Storage for Flatbed and Service Body Trucks, 14 Gauge Steel

#4 · Long Aluminum

4. HEVIKE Aluminum Box

• Dimensions: 48"L x 18"W x 18"H
• Weight: 50 lb
• Material: Aluminum
• Material Type: Aluminum

Best for: Easy-care aluminum flatbed box.

Why it ranks #4: The 48 x 18 x 18-inch aluminum box is expressly listed for flatbed trucks and combines a side-mount format with a cam-lock double barn door.

A smooth aluminum surface makes this 48-by-18-by-18-inch HEVIKE box easier to clean and maintain, while its double barn door gives direct access to stored equipment. The product information also specifies a powder-coated surface intended to resist rain and corrosion for outdoor commercial-vehicle use.

The 48-inch length creates a long compartment for tools or equipment on a trailer, semi truck, or flatbed, and the double barn door supports broad front access. Aluminum construction is corrosion-resistant, while the smooth surface is described as easier to clean during routine maintenance. A powder-coated finish adds protection against rain and corrosion, and the listing identifies the box as lockable. At 50 pounds, it is lighter than the listed 69.1-pound 48-inch steel FGJQEFG box.

Skip it if you require a stated load limit; VEVOR's 36-inch aluminum box lists an 88-pound maximum recommendation.

This suits flatbed and commercial-vehicle owners wanting a 48-inch aluminum box with broad double-door access and a smooth, maintainable surface. The listing gives no maximum load recommendation, so it does not set a stated carrying limit.

Listed on Amazon as: Heavu Duty Aluminum Underbody Truck Tool Box With Cam Lock, Double Barn Door, 48"×18"×18" Side Mount Tool Box for Trailer, Semi Truck, Flatbed Truck

#5 · Two-Box Set

5. Vigorighter Steel Boxes

• Dimensions: 24"L x 12"W x 14"H
• Material: Alloy Steel
• Material Type: Alloy Steel

Best for: Compact two-box steel pack.

Why it ranks #5: The two 24 x 12 x 14-inch steel boxes are explicitly listed for flatbeds, trailers, and trucks, offering separate compact storage locations.

Two 24-by-12-by-14-inch steel boxes give this Vigorighter pack separate underbody storage locations for a truck, RV, trailer, or flatbed. Their powder-coated finish and T-handle latches provide a durable, lockable format, while the compact dimensions can suit smaller spaces than a long single chest.

Each box measures 24 by 12 by 14 inches, making the two-pack useful when separate storage points are preferable to one long enclosure. Alloy-steel construction and a rigid powder-coated finish are specified for heavy-duty, corrosion-resistant use, and the T-handle latch provides lockable access. The listing gives a maximum weight recommendation of 20 pounds, an important boundary for tool selection. Fully welded seams are described as helping keep rain, dust, and grime out during vehicle use.

Skip it if you need to carry more than 20 pounds per box; VEVOR's 36-inch aluminum box lists an 88-pound maximum recommendation.

This suits buyers wanting two compact lockable boxes for light tools or supplies on a flatbed, trailer, RV, or truck. The 20-pound maximum recommendation per listed box is the key boundary when choosing what to store.

Listed on Amazon as: 24 Inch Underbody Tool Boxes for Truck 2 Pack, 24 x 12 x 14 Inch Steel Under Body Storage Box with T-Handle Latch, Waterproof Heavy Duty Toolbox for Pickup Truck RV, Black (Pack of 2)

#6

6. VEVOR Aluminum Box

• Dimensions: 36"L x 17"W x 18"H
• Weight: 28.4 lb
• Material: Aluminum
• Material Type: Aluminum

Best for: Lightweight sealed aluminum storage.

Why it ranks #6: The 36 x 17 x 18-inch aluminum box is intended for truck and trailer underbody installation, with a rubber sealing strip and two keys.

At 28.4 pounds, this 36-inch VEVOR aluminum box is a comparatively light underbody option for trucks, trailers, campers, or pickup racks. Its rubber sealing strip helps keep water out when closed, and the diamond-plate enclosure uses a lockable T-handle latch with keys.

The 36-by-17-by-18-inch size fits a range of vehicle storage locations, including truck or trailer undersides and camper or pickup racks. Aluminum construction is described as rust- and corrosion-resistant, while the rubber sealing strip helps block water when the lid closes. A T-handle latch and two included keys provide lockable access. The 88-pound maximum weight recommendation gives buyers a defined loading boundary, and the 28.4-pound box weight can ease handling compared with heavier enclosures.

Skip it if you need to carry more than 88 pounds; VEVOR's 60-inch steel box has no listed maximum weight recommendation.

This suits buyers prioritizing a lighter, lockable aluminum enclosure for tools or camping gear in a truck, trailer, or camper. Keep its 88-pound maximum recommendation in mind, along with the 36-by-17-by-18-inch dimensions.

Listed on Amazon as: VEVOR Underbody Truck Box, 36"×17"×18" Pickup Storage Box, Heavy Duty Aluminum Diamond Plate Tool Box with Lock and Keys, Waterproof Trailer Storage Box with T-Handle Latch for Truck, Van, Trailer

#7

7. VEVOR Steel Box

• Dimensions: 60"L x 18"W x 18"H
• Weight: 80.3 lb
• Material: Cold Rolled Steel
• Material Type: Cold Rolled Steel

Best for: Long sealed steel storage.

Why it ranks #7: Its 60 x 18 x 18-inch steel chest offers a long storage format, powder-coated finish, full-perimeter rubber gasket, and four keys.

A 60-by-18-by-18-inch body gives this VEVOR steel box a long underbody compartment for tools in trucks, vans, SUVs, or trailers. Its full-perimeter rubber gasket helps block rain and dust, while the powder-coated galvanized steel construction is specified for resistance to rust and wear.

The 60-inch length offers room for longer tools and supplies, while the 18-inch height and depth define the space required beneath the vehicle. Cold-rolled steel and a powder-coated galvanized finish provide a durable enclosure with rust- and wear-resistance described in the listing. A full-perimeter rubber gasket seals the door against rain and dust, and the seamlessly welded body supports outdoor use. The T-handle and four included keys provide lockable access to stored gear.

Skip it if you want a lighter enclosure for easier handling; VEVOR's 36-inch aluminum box weighs 28.4 pounds.

This fits buyers needing long, sealed steel storage beneath a truck, van, SUV, or trailer. Its 60-inch length and 80.3-pound weight call for adequate underbody space and a plan for handling during installation.

Listed on Amazon as: VEVOR Underbody Truck Tool Box, 60 x 18 x 18 Inch Heavy Duty Steel Trailer Storage Box with Lock & Keys, Waterproof Trailer Storage Organizer Under Body Chest with T-Handle for Truck, Van, SUV, Black

#8

8. EASYBERG Aluminum Box

• Dimensions: 36"L x 18"W x 18"H
• Weight: 40.1 lb
• Material: Aluminum
• Material Type: Aluminum

Best for: Lightweight aluminum double doors.

Why it ranks #8: This 36 x 18 x 18-inch aluminum box weighs 40.1 pounds and has a rubber seal, lock, and double barn doors for access.

At 40.1 pounds, this 36-by-18-by-18-inch EASYBERG aluminum box is lighter than the listed steel options in this roundup. Its double barn doors open the front for access, while a rubber seal and corrosion-resistant aluminum suit outdoor truck and trailer storage.

The 6.75-cubic-foot capacity provides space for power tools and jobsite gear without using the vehicle's main cargo area. Aluminum construction is corrosion-resistant, and the rubber seal supports moisture protection for outdoor storage. Double barn doors give access across the front of the 36-by-18-by-18-inch enclosure, which can make reaching stored items more convenient. Its cam lock provides lockable storage, while the 40.1-pound listed weight is a practical consideration for handling during installation.

Skip it if you need a long enclosure for extended tools; HEVIKE's 48-inch aluminum box offers a longer body.

This fits buyers seeking a lighter aluminum box for power tools and jobsite essentials beneath a truck or trailer. Its 36-inch length suits compact storage, but buyers carrying long equipment may need a longer enclosure.

Listed on Amazon as: 36" Aluminum Underbody Truck Tool Box with Cam Lock, Double Barn Door

#9

9. FGJQEFG Steel Box

• Dimensions: 48"L x 18"W x 18"H
• Weight: 69.1 lb
• Material: Steel
• Material Type: Steel

Best for: Long steel trailer enclosure.

Why it ranks #9: The 48 x 18 x 18-inch steel box has a lock and key and is described for outdoor trucks and trailers, but flatbed fit is less specific.

A 48-by-18-by-18-inch steel body gives this FGJQEFG box a long storage footprint for underbed trailers, pickups, and RVs. The product information specifies powder-coated 14-gauge steel, hand-welded seams, and a lock with key, combining a weather-resistant enclosure with basic access security.

At 48 inches long, this box offers an extended compartment for outdoor truck, trailer, pickup, or RV storage. Its 14-gauge steel construction and hand-welded seams are specified to add strength, while the powder-coated surface is described as weather-resistant and corrosion-resistant. A lock and key provide a way to secure stored items. Buyers should weigh the 69.1-pound listed weight when planning handling and mounting, as well as the 18-inch height and depth when allocating underbody space.

Skip it if you want aluminum to reduce box weight; HEVIKE's 48-inch aluminum box is listed at 50 pounds.

This is for buyers wanting a long, lockable steel enclosure on a trailer, pickup, or RV. Its 48-by-18-by-18-inch dimensions and 69.1-pound weight make available mounting space and installation handling important considerations.

Listed on Amazon as: 48'' Heavy Duty Truck Tool Box Steel for UnderBed Trailer Outdoor Car with Lock and Key – 48 x 18 x 18 Inch Black Underbody Toolbox

#10

10. COOLBAG Steel Boxes

• Dimensions: 48"L x 14"W x 16"H
• Material: Alloy Steel
• Material Type: Alloy Steel

Best for: Two-box flatbed storage.

Why it ranks #10: The listing identifies a two-box 48 x 14 x 16-inch steel set for flatbeds, but provides fewer installation and construction details than higher-ranked choices.

This COOLBAG listing supplies a two-pack of 48-by-14-by-16-inch underbody boxes, giving flatbed owners two separate steel storage enclosures. Each is described as having a T-handle lock with keys and a powder-coated finish, useful for dividing tools or supplies between locations on a truck or trailer.

Two 48-inch-long boxes provide separate storage locations, which can help keep different tools or supplies organized across a truck, trailer, RV, or flatbed. The listed alloy-steel construction and powder-coated finish suit underbody use, while the weathertight feature and locking T-handle with keys address protection and access security. Each box measures 48 by 14 by 16 inches, so buyers can assess the dimensions for available mounting space; the listing specifies boxes as included components.

Skip it if you need a stated load limit before selecting a box; VEVOR's 36-inch aluminum model lists an 88-pound maximum recommendation.

This pack suits flatbed or trailer owners who want two separate, long steel storage boxes with locking T-handles. Check that two 48-by-14-by-16-inch enclosures suit the mounting space, since the listing gives no load recommendation.

Listed on Amazon as: 2 Pack Underbody Truck Tool Box, 48"x14"x16" Heavy Duty Steel Storage Chest with T-Handle Lock & Keys, Waterproof Under Mount Toolbox Organizer for Pickup, Trailer, RV, Flatbed, Powder Coated