This UWS underbody tool box bolts beneath the deck of a flatbed, dump body or trailer, where it takes up no deck space at all. It gives you 9.2ft³ behind a lockable stainless T-handle, with a full-perimeter drip rail and stainless cables holding the door at 90 degrees. The tub is a single piece of 0.058" aluminum and a MicroSeal gasket runs the full perimeter of the opening to keep rain and dust out. This body style uses a cable-supported door rather than UWS's RigidCore foam-filled lid, which is fitted to their chest, side and crossover boxes. The finish is bright aluminum diamond plate. This is the heavy-packaging version of the box: mechanically identical to the standard part, but crated for parcel carriage so it can ship without freight. UWS designs, fabricates and welds it in Florida and backs it with a limited lifetime warranty.
What's Included:
UWS 48" Underbody Tool Box in Bright Aluminum, part EC40101
2 keys
NOT included: mounting hardware. UWS states you must supply your own bolts to suit your truck
UWS installation sheet, product literature and warranty information
Features
Stainless Steel Door Support Cables Stainless cables carry the door when it is open, holding it steady at 90 degrees instead of letting it swing. They will not stretch or corrode through the way a plain steel cable does on an underbody box that is constantly wet.
Full 90-Degree Door Opening The door drops to a full 90 degrees so the whole opening is clear. You can slide long items straight in and out instead of angling them past a half-open door.
Lockable T-Handle A single lockable T-handle opens the door with one hand, so you can keep hold of what you are carrying. It is a compression handle, so it pulls the door tight against the seal each time it is latched.
MicroSeal Weather Gasket A MicroSeal gasket runs the full perimeter of the opening and compresses as the lid closes, sealing out rain, road spray, dust and the fine grit that ruins bearings and fastener threads. It is the part of a tool box most owners only think about after they have found standing water inside a cheaper one.
Full-Perimeter 1" Drip Rail A 1" drip rail wraps the entire door opening and sheds water away from the seal rather than letting it run in over the lip. On a box mounted under a flatbed, where road spray comes at it from below as well as above, this is what keeps the contents dry.
Part of a Full Size Range UWS builds this body style in several lengths, so you can match the box to the bed rather than accepting whatever happens to be in stock. This one is the 48" version.
Designed, Fabricated and Welded in Florida UWS designs, fabricates and welds its tool boxes at its own plant in Florida. That is unusual at this price and it shows up in the things that are hard to fix later: consistent weld quality, lids that sit square, and gaskets that actually meet all the way round.
Limited Lifetime Warranty UWS backs the box with a limited lifetime warranty, with one year on the finish and one year on parts. That is the manufacturer telling you what it expects the welded aluminum structure to do over the life of the truck.
Fitment & Compatibility
Application
Fit
Flatbed truck, under the deck
✓ Yes, ideal application
Dump body or trailer frame
✓ Yes, provided the frame rail will take the mounting
Conventional pickup bed
✗ No, there is no underbody space on a standard pickup
Fit guidance: This box mounts beneath the deck of a flatbed, dump body or trailer, between or below the frame rails, so it uses no deck space at all. It is 48" long, 19" deep and 18" tall, so check the clear space between your crossmembers and the ground clearance you will have left once it is loaded. Mounting hardware is not included; UWS states you must supply bolts to suit your truck.
Specifications
UWS Part Number: EC40101
Equivalent Standard Part Number: TBUB-48 (same box, standard packaging)
Box Style: Underbody Tool Box
Finish: Bright Aluminum diamond plate
Material: 0.058" one-piece aluminum
Storage Capacity: 9.2ft³
Overall Length: 48"
Overall Width: 19"
Overall Height: 18"
Door Style: Single-Door
Latch / Handle: T-Handle
Weather Sealing: MicroSeal full-perimeter gasket
Installation Difficulty: Easy
Product Weight: 40 lb
Shipping Weight: 55.01 lb
UPC: 672078082211
Warranty: Limited lifetime, one-year finish, one-year parts
Origin: Designed, fabricated and welded in Florida, USA
Installation
Type: Bolt-in · Time: About 30 to 60 minutes · Tools: Socket set, drill and bit if your application is not pre-drilled, tape measure, marker; a second person to lift and hold the box · Difficulty: Intermediate, a fabricator or upfitter is worth involving
Underbody boxes are usually mounted on brackets to the frame rail or the underside of the deck. Confirm the clear space between crossmembers, check the ground clearance you will have with the box loaded, and keep the mounting clear of the exhaust, air lines, driveshaft and any moving suspension component. This is the one box in the range where a fabricator or an upfitter is worth involving if you are not confident.
Resources
Everything you need for your UWS 48" Single-Door Underbody Tool Box, Bright Aluminum, in one place.
Warranty. UWS limited lifetime warranty on the box, with one year on the finish and one year on parts. Damage from overloading, accident, modification or improper installation is not covered, and the warranty is offered to the original purchaser.
Free shipping. This item ships free to the lower 48 states. Because it is an oversized item, it ships by freight and typically arrives in 3 to 7 business days.
Inspect on delivery. Please inspect the packaging before signing. If you see any damage, note it on the delivery receipt and contact us right away, and we will make it right.
About UWS
UWS, United Welding Services, has been welding aluminum truck boxes in Florida since 1988. It is now part of the Lippert and CURT Group family, which is what gives a box at this price a real dealer network, real parts support and a warranty that means something years later. What has not changed is where the boxes are made: UWS designs, fabricates and welds them at its own plant rather than importing finished bodies, and that is visible in the details that cannot be fixed after the fact, such as square lids, consistent welds and gaskets that meet cleanly all the way around the opening.
This underbody tool box is not one of the RigidCore lid models, because it does not have a lid: it is built around a door carried on stainless steel cables. What it shares with the rest of the range is the part that matters most, the 0.058" one-piece aluminum tub, thicker than most of the competition and immune to the rust that eventually kills a painted steel box, and the MicroSeal full-perimeter gasket that keeps rain, road spray and fine grit out of your tools.
Prestige Truck is an authorized UWS dealer. Every box we ship is new, factory-packed, covered by the full UWS limited lifetime warranty and supported by UWS's US-based parts and service team.
Compare The Range
How this compares to similar models
The closest alternatives side by side, so you do not have to keep tabs open.
Model
This OneUWS 48" Single-Door Underbody Tool Box, Bright Aluminum (EC40101)
UWS buries a box in mud and then turns a pressure washer on it to show what the MicroSeal gasket keeps out.
Worth two minutes if you are deciding between this and a cheaper box with a plain foam strip, because sealing is the thing you only notice once it has failed.
UWS Damage-Free Delivery
This part is the heavy-packaging version of the box, crated so it can travel by parcel carrier instead of freight.
This short UWS film shows the packaging system that makes that possible and what the carton should look like when it reaches you. Inspect the carton on arrival and photograph any damage before you sign.
Frequently Asked Questions
Straight answers on specs, fit and support
What are the actual dimensions, and will it fit my truck?
The box is 48" long, 19" deep and 18" tall overall, and it holds 9.2ft³. Measure the clear space between your frame crossmembers and check the ground clearance you will have left with the box loaded.
Is the mounting hardware included?
No. The carton holds the box and 2 keys. UWS states that you must supply your own hardware to suit your truck.
What is the difference between this and the standard UWS part?
Nothing about the box itself. UWS states that this part is identical to #TBUB-48, with the only difference being that it is heavily packaged so it can travel by parcel carrier rather than by freight. You get the same box, the same warranty and, usually, a faster and cheaper delivery.
How well does it keep water out?
A MicroSeal gasket runs the full perimeter of the opening and compresses as the door closes. This model also has a 1" drip rail wrapping the whole door opening, which sheds water away from the seal instead of letting it run in over the lip. No tool box is a submarine, and a box that is pressure washed straight at the seam or parked nose-down in standing water can still take some in, but in normal service it stays dry inside. Keep the gasket clean and it will keep sealing.
What is the finish, and how does it hold up?
Bright aluminum diamond plate, which is the mill finish of the aluminum itself rather than a coating. It cannot chip or peel because there is nothing on top to come off, and aluminum does not rust. It will dull and pick up a patina over the years, which most owners either like or polish back.
Does the lid stay open on its own?
The door drops to a full 90 degrees and is held there by stainless steel cables, so the whole opening stays clear while you load. The cables are stainless rather than plated, which matters on a box mounted this close to the road.
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