A: Absolutely. With our formed rain gutter, inset door and crush weather-stripping, you won’t have any issues with water seeping into your box.
Drop Door Semi Box
keep your straps, tarps, and tools secure and accessible.
Drop Door Semi Box
Designed to last a million miles
- Lifetime Warranty since 1980 = over-engineered and overbuilt
- American Made by skilled tradesmen
- Built with only premium materials and components
- Sealed for protection from thieves and weather
- Multiple finish options
- Lifetime Warranty – Retire your truck but keep the box
Starting at $574
The Highway Products Drop Door Box is the only underbody toolbox designed and built to last a million miles. With structural corner gussets, angle braces, and bottom face stiffeners you can be sure that this underbody toolbox will not fail to the tests of the road. Like everything else we build, the HPI Drop Door Box comes with Highway Products’ lifetime warranty.
WHY AN HPI™ Drop Door Semi Box
Highway Products boxes are completely reinforced to prevent the torsional forces that causes welds to crack and boxes to fail. The structure is the secret to our Million Mile Boxes.
You will never see bungies holding together an HPI Drop Door Box. Thanks to ¼” stainless steel hinges with 3/8” knuckle secured by torx screws. Stainless steel T-Handles with 3/8 locking rods.
We use 1/8” 5052 marine grade aluminum to ensure you won’t deal with rust or deterioration of your toolbox over the years on the road in all different conditions.
Upgrade from Smooth Aluminum to Polished Stainless Steel Doors, or even Powdercoat your boxes for a unique look
Perfect to mount under bodies, or use for a variety of applications.
Everything build at Highway Products gets our Lifetime Guarantee
WHY AN HPI™ Drop Door Semi Box
It’s all about the structure
Highway Products boxes are completely reinforced to prevent the torsional forces that causes welds to crack and boxes to fail. The structure is the secret to our Million Mile Boxes.
Doors that never fail
You will never see bungies holding together an HPI Drop Door Box. Thanks to ¼” stainless steel hinges with 3/8” knuckle secured by torx screws. Stainless steel T-Handles with 3/8 locking rods.
Premium Materials
We use 1/8” 5052 marine grade aluminum to ensure you won’t deal with rust or deterioration of your toolbox over the years on the road in all different conditions.
Choose from different finishes
Upgrade from Smooth Aluminum to Polished Stainless Steel Doors, or even Powdercoat your boxes for a unique look
Versatile use boxes
Perfect to mount under bodies, or use for a variety of applications.
Built to Last Forever
Everything build at Highway Products gets our Lifetime Guarantee
Checkout some photos and videos of Drop Door Semi Box.
Specification sheet: Drop Door Semi Box
1.) Are these waterproof?
2.) I carry a lot of heavy tools with me, will this be a problem?
A: They aren’t called the million mile boxes for nothing! As long as you have your boxes mounted correctly you’re good to go.
3.) Do you offer mounting brackets?
A: Yes! Give one of our sales specialists a call today to discuss your specific mounting needs.
4.) Can you build this box to my specifications?
A: Yeah, let’s do it! Check out our Custom Semi Box page for more information.
5.) Can I get chains on the doors?
A: When ordering, simply ask your sales rep for a chain kit and we can add that to your order.