The design of the Nano TorqBar DX is very clever, essentially offering three separate torque wrenches and a bunch of useful bits in a supremely small and compact form. The handle (with two bits and one TorqBit) was a regular passenger in my travel case throughout the season, and if you really wanted to slim down, you could even use ditch the handle entirely and just add the TorqBit and hex or Torx fitting to any tool provided it’s equipped with a 6mm socket.
That said, tool companies can pack in as many features as they’d like into their torque wrenches, but the only things that really matter are their accuracy and repeatability. When judged along those lines, the Nano TorqBar DX’s sheen starts to wear off.
Inside each tiny TorqBit is a clutch-type mechanism that automatically limits how much force can be applied to a bolt — or at least, that’s what it’s supposed to do.
I measured each TorqBit’s accuracy using a CDI CompuTorq digital torque wrench (which is made by Snap-On, one of the top names in torque wrenches). In addition to displaying the applied torque on the LCD screen, the CompuTorq will also record the maximum torque that was actually applied — perfect for evaluating preset wrenches like this. Using one to drive the other, I tested each of the included TorqBits five times and recorded the following maximum values that were applied before each bit’s self-limiting clutch mechanism kicked in:
4Nm TorqBit: 3.87/4.04/4.17/4.02/3.98Nm (average: 4.016Nm)
5Nm TorqBit: 5.30/5.37/5.35/5.43/5.58Nm (average: 5.406Nm)
6Nm TorqBit: 6.14/6.12/6.20/6.14/6.33Nm (average: 6.186Nm)
The 4Nm and 6Nm TorqBits were quite accurate, edging just slightly over the prescribed limits and falling well within the accepted range. The 5Nm TorqBit, however, strayed almost 10% from the stated value. That’s probably still not enough to do actual damage to most components that have a 5Nm torque rating, but I certainly would have preferred to see that value fall more in line with the other two, if for no other reason than the fact that 5Nm is the most common torque value used in most lightweight components.
The handle serves double duty as a miniature case of its own, housing one TorqBit and two bits as needed.
Making matters worse, those values creep worrisomely upward depending on how the force is applied. All of the above values were recorded while applying torque slowly and judiciously, listening carefully for the muted click that indicates when you’ve hit the desired figure. In theory, it shouldn’t matter how fast or slow you apply torque in a clutch-limited design like this, but when turning the wrench more quickly and forcefully, each TorqBit applies almost a full Nm more torque than desired.
So would I still use the Nano TorqBar DX? Yes, and in fact, I do still keep it in my travel case. However, I probably would choose a more accurate wrench for any truly featherweight items that presumably have a narrower window of safety, and am very careful to use it slowly so as not to inadvertently overload any bolts. The Nano TorqBar DX may be easy to use, but it’s also easy to use incorrectly — with potentially damaging results.
