Knaack 79-H StorageMaster Piano Box with ThermoSteel

Knaack 79-H job box with ThermoSteel
PTR Review
  • Build Quality 10.0
  • Features & Options 9.0
  • Ease of Use 10.0
  • Security 10.0
  • Value 8.0

The ThermoSteel feature of the Knaack 79-H StorageMaster is almost certain to be a hit for the northern crowd during the winter months.

Overall Score 9.4 (out of 10)

If you’ve been in the construction industry for any amount of time, you’ve either had tools stolen from you, or you’ve known someone who’s had that happen to them. It’s a terrible thing, but it happens—and sometimes offsite storage of tools simply isn’t possible or practical. For that, your options are to use a trailer (which itself can be stolen), or secure an on-site job box with your tools and accessories stored within. The advantage of a job box is that it’s made out of very thick gauge steel and can be secured to the job site in a number of ways. The Knaack 79-H StorageMaster Piano Box is one of the company’s larger steel job site storage boxes, and we got an opportunity to check it out along with its newest optional feature: ThermoSteel.


The Knaack 79-H StorageMaster Piano Box is 48 inches wide and slightly taller than that in height (with the lid closed). It’s internal volume is 36.2 cubic feet, and it’s the perfect solution for anyone wanting to store tools and important items on-site. Like most of the Knaack job boxes, you can order optional casters, and the form factors include options for shelves and/or front drawers depending upon your particular needs.

Knaack ThermoSteel Job Boxes

The big deal with this Knack job box is that it comes with their new ThermoSteel technology. This is a heat radiating “electric blanket” of sorts which keeps everything at the optimal temperature. That helps your lithium-ion batteries stay ready for use and also helps maintain the condition of your power tools, accessories, and adhesives so that they don’t freeze on the job site. The idea is that you would plug in the ThermoSteel heating system once the temperature drops to 40 degrees or below. This not only protects your equipment, it keeps adhesives and other materials in a “ready-to-use” state. While it’s never really snowing here in Central Florida, we do have our share of cold days where the temperature hits near freezing—making this a handy solution (albeit one that our northern Pros will appreciate on a much more regular basis!)

Knaack 79-H ThermoSteel
Under this radiant sheet steel is the ThermoSteel system, an electric thermal blanket that radiates heat to the entire box, keeping your tools and adhesives at a safe and proper temperature, so they’re ready to go when you are.

The Knaack 79-H StorageMaster piano box is a rugged, but simple design with a bi-fold lid that allows it to raise completely and fold flat out of the way. That means you don’t have to worry about clearance for either your head or your tools when you store and remove things from the StorageMaster job box.

Knaack 79-H front

Unboxing the Knaack 79-H StorageMaster Piano Box

Since the Knaack 79-H StorageMaster Piano Box is just 48-inches wide, we were able to get it loaded onto the bed of a 2015 Ford F-150 and take it to the Pro Tool Reviews Shop whee we unloaded it and prepped it for photography and use as a catch-all for our larger equipment. The Knaack 79-H came on a pallet with plenty of corner protection and thick corrugated cardboard wrapped around it to keep it safe.

Knaack 79-H shipping

The steel casters for the Knaack 79-H came in a separate box and installed easily enough. There are two fixed wheels and two locking swivel wheels. We liked the presence of grease points on the wheels to keep them running smoothly.

Knaack 79-H Piano Box casters
The grease points on the casters will ensure many years of smooth operation

Knaack 79-H StorageMaster Piano Box Specs & Features

  • ThermoSteel heated storage
  • Watchman IV Lock System with recessed lock housing
  • Optional wheel casters
  • Four-way skid access from any side
  • Recessed side handles
  • Piano box lid supported with dual gas struts
  • Heavy-duty hinges
  • Powder-coat finish
  • Improved ball stud bracket
  • Height (closed/open): 49 in./78 in.
  • Width: 48 in.

Using the Knaack 79-H Piano Box

The Knaack 79-H has the same thick gauge steel you’ve come to expect from a good quality job box, and the dual gas struts provide a nice assist when opening the box lid.

Knaack 79-H lifters
Knaack 79-H latch external

The Watchman IV latch system is designed to be used with a Master Lock No. 1, No. 5, or American Lock No. 50. You can use an equivalent sized lock, but pay attention to the installation guide for the required dimensions. The Watchman IV design is such that a properly-sized lock prevents the Knaack 79-H latch from physically being able to slide into the open position—thus securing the lid from opening. If you’re like me, wheeling the entire job box away isn’t going to be practical either (plus, you can chain it in place or keep it indoors, further securing your tools). While not foolproof—no solution is—it’s a great system that makes it hard to get into unless you actually pick the lock itself (you can’t access the steel of the lock to use bolt cutters or a saw).

Knaack 79-H piano box latch
Inside the Watchman IV lock system.

We stored all of our larger tools in the Knaack 79-H StorageMaster piano box along with some items that don’t do well in freezing weather. We loved the design of this box—there’s a ton of storage, and the shelving and vented steel door is a great design. There’s also plenty of access to run power and splitters between the top and bottom sections, so you can keep battery chargers in the box as well to recharge your tool batteries on-site overnight. If you want a bottom drawer (or “junk trunk” as they call it), opt for the slightly heavier 79-D or 79-DH model.

Knaack 79-H job box storage
You can store an ample amount of tools in the Knaack 79-H job box, and there’s no doubt they’ll be there when you get back.

Even for corded tools or battery powered products with modern lithium-ion batteries, keeping your valuable tools secure and warm when stored will increase their usefulness and life expectancy. Going from freezing to 100-plus degrees within a span of seconds isn’t really good for any tool…and if you’re trying to use frozen adhesives, well, forgeddaboudit. With the Knaack 79-H and other job boxes they sell with their ThermoSteel option, you won’t have to worry about this any longer. You can pick up the Knaack 79-H for just over $1,400 at Acme Tools…that’s a lot cheaper than having to replace all of your tools because you didn’t properly secure them.

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