ATB A-SR55 Aluminum Underbody Truck-Trailer Tool Box, Double Side Open Doors, Bar Latch Lock
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Features
- Super Heavy Duty Aluminum: ATB builds the A-SR55 Series from aluminum it calls super heavy duty, made for high-capacity underbody storage on trucks and trailers.
- Double Side Open Doors: Double side open doors give convenient truck side access, so you can load and unload from either side of the opening.
- Stainless Steel Bar Latch Lock: The doors close on a stainless steel bar latch lock that ATB chose for secure, corrosion-resistant closure.
- Concealed Gutter and Weather Seal: A fully concealed gutter and an automotive weather seal help keep water and road spray out of the box.
- Smooth or Stainless Mirror Doors: The body is smooth aluminum; pick smooth aluminum doors to match or stainless mirror doors for a polished look.
- Sizes for Common Underbody Spaces: Choose 18" or 24" tall, 18" or 24" deep and 36" to 96" wide to suit the space under your deck or trailer.
Description & Fitment
The ATB A-SR55 Series is an aluminum underbody box for trucks and trailers that ATB calls super heavy duty. Double side open doors let you reach the contents from either side, and they close on a stainless steel bar latch lock. A fully concealed gutter and an automotive weather seal help keep the inside dry. It is made in Blanchard, North Dakota.
Fitment & Compatibility
How to choose: measure the open space under your deck or trailer (width between obstructions, depth from the frame outward, and the drop from the deck to a safe ground clearance), then pick an 18" or 24" tall box that fits with room for the doors to swing.
Widths run from 36" to 96"; the 72", 84" and 96" widths come 24" deep.
Doors: -S part numbers have smooth aluminum doors, -M part numbers have stainless mirror doors. Order the mounting kit separately: M2100C for C-frame, M2450D or M2700D for under deck.
Fits: Truck and trailer underbody spaces (measure your mounting area; see the size table)
About ATB
American Truckboxes (ATB) builds aluminum and steel truck boxes, tanks and storage in Blanchard, North Dakota, and has done so for more than 25 years, by its own account. Its range covers pickup crossover, side-mount, chest and drawer boxes, service-truck boxes and packs, fuel tanks, and heavy-truck and trailer boxes.
Authorized ATB dealer. Prestige Truck is an authorized ATB dealer: every box on this page is built by ATB to the part number shown.
Frequently Asked Questions
Will it fit under my trailer?
ATB offers the A-SR55 in several heights, depths and widths to suit common underbody spaces. Measure the clearances and the mounting area under your trailer before you order, and contact us if you want a second check.
How do I measure for an underbody box?
Measure the open space under the deck or trailer: the width between obstructions, the depth from the frame outward and the height from the deck down to a safe ground clearance. Pick the box that fits inside all three with room for the doors to open.
Does the box come with mounting brackets?
No. ATB sells the mounting kit separately: M2100C for C-frame mounting, or M2450D or M2700D for under-deck mounting. Contact us if you are not sure which kit suits your truck or trailer.
Is the A-SR55 weather sealed?
Yes. ATB builds it with a fully concealed gutter and an automotive weather seal, and the doors close on stainless steel bar latch hardware.
What is the difference between the smooth and stainless mirror versions?
The body is smooth aluminum on every version. Part numbers ending in -S have smooth aluminum doors; part numbers ending in -M have stainless mirror doors.
Can I get a custom size or a steel version?
ATB builds custom sizes and offers this underbody box in steel on request. Contact us with the dimensions you need and we will get you a quote.
Installation
- 1/2" ratchet wrench
- 1/2" wrench
- Tape measure
- Drill
- 3/8" drill bit
Here's the short version. Follow ATB's install sheet (below) for your truck's exact positions and hardware.
- Check all parts against the parts list and make sure there is room to mount the box.
- Set the box where it will mount to confirm the fit. The box is not predrilled; drill as close to its outside edges as possible.
- For a bed mount use an M2200 series bracket, for a frame mount an M2000 or M2100 series bracket; install the bracket first.
- Mark four holes on the box bottom and drill them with a 3/8" bit, then set the box back and mark the pattern on the mounting surface or brackets.
- Remove the box and drill four 3/8" holes at the marks.
- Fit the bolts with washers from the box side through the surface or bracket, add a flat washer and lock nut and tighten securely.
Stuck on a step?
- A-SR55 Series underbody box
Specifications
| Brand | ATB |
|---|---|
| Series | A-SR55 |
| Type | Underbody box |
| Material | Aluminum |
| Body finish | Smooth aluminum |
| Doors | Double side open doors |
| Door configuration | Left-driver |
| Lock | Stainless steel bar latch lock |
| Weather protection | Fully concealed gutter, automotive weather seal |
| Mounting | Mounting kit sold separately (M2100C for C-frame; M2450D or M2700D under deck) |
| Made in | USA |
| Part number | A-SR55-181836DL-S |
| Part # | Size | Door and Lid Finish |
|---|---|---|
| A-SR55-181836DL-S | 18"H x 18"D x 36"W | Smooth Aluminum |
| A-SR55-181836DL-M | 18"H x 18"D x 36"W | Stainless Mirror |
| A-SR55-181848DL-S | 18"H x 18"D x 48"W | Smooth Aluminum |
| A-SR55-181848DL-M | 18"H x 18"D x 48"W | Stainless Mirror |
| A-SR55-181860DL-S | 18"H x 18"D x 60"W | Smooth Aluminum |
| A-SR55-181860DL-M | 18"H x 18"D x 60"W | Stainless Mirror |
| A-SR55-182436DL-S | 18"H x 24"D x 36"W | Smooth Aluminum |
| A-SR55-182436DL-M | 18"H x 24"D x 36"W | Stainless Mirror |
| A-SR55-182448DL-S | 18"H x 24"D x 48"W | Smooth Aluminum |
| A-SR55-182448DL-M | 18"H x 24"D x 48"W | Stainless Mirror |
| A-SR55-182460DL-S | 18"H x 24"D x 60"W | Smooth Aluminum |
| A-SR55-182460DL-M | 18"H x 24"D x 60"W | Stainless Mirror |
| A-SR55-182472DL-S | 18"H x 24"D x 72"W | Smooth Aluminum |
| A-SR55-182472DL-M | 18"H x 24"D x 72"W | Stainless Mirror |
| A-SR55-242436DL-S | 24"H x 24"D x 36"W | Smooth Aluminum |
| A-SR55-242436DL-M | 24"H x 24"D x 36"W | Stainless Mirror |
| A-SR55-242448DL-S | 24"H x 24"D x 48"W | Smooth Aluminum |
| A-SR55-242448DL-M | 24"H x 24"D x 48"W | Stainless Mirror |
| A-SR55-242460DL-S | 24"H x 24"D x 60"W | Smooth Aluminum |
| A-SR55-242460DL-M | 24"H x 24"D x 60"W | Stainless Mirror |
| A-SR55-242472DL-S | 24"H x 24"D x 72"W | Smooth Aluminum |
| A-SR55-242472DL-M | 24"H x 24"D x 72"W | Stainless Mirror |
| A-SR55-242484DL-S | 24"H x 24"D x 84"W | Smooth Aluminum |
| A-SR55-242484DL-M | 24"H x 24"D x 84"W | Stainless Mirror |
| A-SR55-242496DL-S | 24"H x 24"D x 96"W | Smooth Aluminum |
| A-SR55-242496DL-M | 24"H x 24"D x 96"W | Stainless Mirror |
Warranty, shipping & returns
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Warranty
ATB covers its standard truck boxes with a 60-month (5-year) limited warranty for the original purchaser; it is not transferable.- For a warranty claim, contact us with your order number and photos and we will work it through with ATB.
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Shipping
Ships by freight from the ATB factory in Blanchard, ND; lift-gate delivery available.- Alaska, Hawaii and Canada: contact us for a freight quote before you order.
- We email your tracking details as soon as it ships.
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Inspect on delivery
Check the box when the freight arrives, before the driver leaves: look over the lids, doors, corners and welds for dents, scratches or shipping damage. Note any damage on the delivery receipt and send us photos. Check it as soon as it arrives.- Look for crushed ends, punctures or tears in the carton.
- If something looks wrong, take photos of the box and the parts (and if a driver asks you to sign, note the damage on the receipt).
- Open the box and check the parts against the parts list before you install.
- Email support@prestigetruck.com right away with your order number, a short note and photos. We send a replacement or a full refund at no cost to you.
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30-day returns
Return it within 30 days of delivery, unused, in the original packaging, with proof of purchase.- Email support@prestigetruck.com with your order number. We reply within 1-2 business days with instructions.
- Damaged, defective or wrong item: we send a prepaid label or arrange a pickup.
- Changed your mind: you pay return shipping. No restocking fee.
- Refunds go back to your original payment method within 7 business days of approval. See our returns policy.