Here is the no-filler answer: if the used Knaack tool box you are looking at has solid welds, working lock cylinders, and no rust-through on the bottom, buy it—you get most of the service life of a new box at a fraction of the price, and you should spend the difference on replacement locks and casters before it goes to work. I review every piece of tool storage our crews receive—roughly 200 boxes, carts, and chests a year—and the used Knaack units we bought did the same job as the new ones.
To be clear about my angle, I am not in sales. I work for a regional contractor, and part of my job is approving or rejecting the storage we assign to field teams. We settled on Knaack tool storage for truck boxes, job boxes, and weld boxes because of the steel construction, the lock options, and a less obvious reason: replacement parts are available. That last point matters more than you would think. It is also why the used market is worth taking seriously.
If you remember nothing else, remember this: price is what you pay on day one. Total cost is what that box costs over the next five to ten years.
Knaack tool storage is about total cost, not sticker price
In early 2025, we bought four used Knaack truck boxes for about 47 percent of their new-list price. All four needed attention before they could go into service. Two needed replacement lock cylinders. One needed a caster. The parts and shop labor came to roughly 6 percent of what the new boxes would have cost, and after that, nobody could tell them from new units without looking closely.
I do not have hard national data on used Knaack pricing, and anyone who gives you a precise price without knowing your market is guessing. Based on what we see on dealer surplus lots and local marketplace listings, a serviceable used Knaack tool box for sale can show up at anywhere from a third to two-thirds of new price. The exact discount matters less than the condition of that particular box. Knaack steel boxes have already taken the big depreciation hit, and they still have years of service left in them.
The common mistake is to stop at the sticker price. A $600 used box that needs $200 of parts is a worse deal than a $750 used box that is ready to mount. Run the total-cost math before you negotiate.
What to inspect on a used Knaack tool box for sale
Here is the condensed checklist I use when a used box arrives for review:
- Lock cylinders and keys. Each lock should open and close smoothly with the key that comes with it. Look for drill marks or replaced screws around the cylinder. If keys are missing, factor in replacement cylinders.
- Welds and corners. Inspect every corner and seam. Hairline cracks near handles, hasps, or hinge plates are a red flag.
- Bottom pan and rust. Surface rust is normal; rust-through is not. Check the bottom from the inside, not just underneath.
- Hinge and lid alignment. The lid should sit square and close without forcing it. Misalignment usually means a bent frame.
- Mounting points. On a truck box, check the brackets and bolt holes. Wallowed-out holes or stress cracks near mounts tell you the box has been overloaded or loose on the road.
- Weather seal. Push down on the lid after closing it. You should feel some resistance from the seal. A flat or cracked seal lets rain in, and rain inside a box is how rust starts.
- Casters and handles. Casters should roll and swivel without binding. Handles are worth replacing if they feel loose.
Cosmetic dents do not bother me. A box that has been through real jobsite use and still locks and seals is a better buy than a freshly painted box with hidden problems. Besides, a dented box is less likely to be chosen as a theft target than a pristine one. Corrosion, not dents, is what ends a steel box.
On 'theft-proof' claims and what security actually means
I will not call any storage box theft-proof, and you should be suspicious of anyone who does. Per FTC advertising guidelines (ftc.gov), claims need to be truthful and substantiated, and no portable steel container can honestly claim it cannot be opened. The realistic goal is to slow a thief down and make your truck less attractive than the next one. Knaack does that with a welded steel body and a lock designed for repeated use, which is why I specify it. I also remind our crews not to leave the key in the lock. A good lock does not help when the key is sitting in it.
When repairing beats replacing
Repairability applies to the contents of the box, too. If a strap wrench in your kit has a cracked strap, you do not throw the wrench away; you order a No. 5 strap wrench replacement strap and keep the tool in service. The same logic applies to a Knaack box with worn casters: replace the casters, not the whole box. Replacement locks, cylinders, handles, and seals are part of the ownership experience. Use them.
But there is a line. I get asked, can you weld a hydraulic cylinder? Yes, a skilled shop can, but it is usually the wrong repair. Welding heat can warp the barrel and damage the rod surface, and a cylinder that fails under pressure is dangerous. The same line exists for tool boxes. A crack in the outer skin of a steel box can be welded. A crack at a hinge mount, or at the bracket that holds a truck box to the bed, is structural. Those boxes get replaced, not patched.
A quick screwdriver set review, because the inside matters too
When we set up a storage box, we also set up the tool kit, and people ask me what should go inside. I will save you the usual screwdriver set review and give the short version: buy screwdrivers with a full-length steel core running through the handle, a hex bolster on the shaft so a wrench can turn it, and tips that fit the fasteners you actually use. Everything else is marketing. A secure box will not make a bad screwdriver turn a screw better, so store good tools in the box and inspect both at the same time.
The cases where I recommend buying new
Used is a value play, not a religion. I would buy a new Knaack box when you need a manufacturer warranty in your company's name, when you need a uniform fleet look, when you cannot wait for the right used unit to appear, or when the used box shows signs of structural repair. In those situations, new is the lower-risk total-cost answer.
I also want to be honest about the limits of my advice. This approach works for us because we have a shop that can re-key cylinders, mount boxes, and swap casters. If you are a one-truck operator and the box has to work the day it arrives, the calculus changes. I don't have hard data on how used Knaack boxes perform after a decade of service, but what I can tell you from pulling boxes out of service is that storage units fail at locks and hinges first, not at the steel shell. If the shell is sound, you are buying a box with real life left in it.
One more boundary: if your tools never sit unattended, almost any lockable storage will do. My recommendation is about jobsite reality, not brand loyalty. But for an unattended truck or a shared site, a used Knaack that passes the checklist is one of the smartest tool-storage purchases I know. It is how I would spend my own money.
