I couldn’t help myself, I purchased a Kobalt Multi Drive Wrench for review (more info about the new tool here). The full hands-on review of the universal wrench is in the works, but I wanted to share these photos about how well (or poorly) the wrench’s sockets fit fasteners.
Last year, all of the dog bone wrenches on the market had 6-point sockets. Even Black & Decker’s new ratcheting ReadyWrench still features 6pt sockets. Kobalt’s Multi Drive Wrench, on the other hand, features universal spline sockets that are also designed for both SAE and metric compatibility.
Visualize a 12pt combination wrench or socket. Now imagine that the tolerances were loosened up and the wrench or socket widened so that it fit both SAE and comparably sized metric fasteners. Then change the drive pattern from 12pt to spline, and you have a universal socket. I’ll let the photos do most of the talking.
Note: each pair of images consists of two photos, with the second being a cropped/zoomed-in version of the first.
I started off by testing a 5/16″ bolt (1/2″ wrench size) with a common 6-point hexagonal socket. As you can see in the above images, the fit is fairly tight, without much wiggle-room. This is why 6pt sockets are less likely to round-off fasteners than 12pt sockets that offer a less substantial fit.
I then took the 5/16″ bolt and fit it into the Multi Drive Wrench’s 1/2″/13mm socket, as shown below. There is a LOT of wiggle room. This makes the wrench a bit unsteady to use, something that will be covered in our upcoming hands-on review. Scroll back up to take another look at the same bolt in the 6pt socket.
The above photos show how much wiggle-room there is in the Multi Drive socket. I then reoriented and straightened the bolt in the Kobalt wrench and took another photo (below). Without a doubt the Multi Drive’s socket-fastener fit is quite poor compared to a 6pt socket and even a 12pt wrench (not photographed)!
Just looking at the above images, it is clear that the Multi Drive socket design greatly reduces socket-fastener contact area compared to conventional 6pt sockets. This makes it much easier to round-off and damage fasteners in higher torque applications.
I then took an M6 (10mm wrench size) bolt and tested its fit with an ordinary 6pt socket. Again, the fit appears to be pretty good.
The same M6 bolt was then placed in the corresponding 10mm Multi Drive socket.
The final test was to take an M8 bolt (13mm wrench size), and to test it in the 1/2″/13mm socket that also fits the 5/16″ bolt. The socket’s fit of the 5/16″ bolt was disappointing, so I figured that maybe it was closer in size to 13mm than 1/2″. After all, 13mm is equivalent to 0.512 inches.
It appears that the universal socket actually fit the M8 fastener a bit better than it did the 5/16″, but was not nearly tight enough to guarantee against potential fastener damage.
Needless to say, I am disappointed about the fit of the Multi Drive’s sockets in regard to standard 6pt hex fasteners. Yes, they can also fit a variety of other fastener styles – spline, square, spline, etc, but I very rarely come across these types. The Multi Drive is being marketed towards consumers. How many non-hex fasteners do consumers often come across?
Maybe these examples are over-emphasizing fastener fit and exaggerate the gaps of surface contact. Maybe the wrench will fit fasteners better in real-life tests and applications. Maybe the wrench is better suited for just-in-case or general purpose applications. Or maybe it will round off a fastener at the worst possible time.
What I do know for certain is that, speaking as a consumer, I don’t trust the fit of these sockets on 6pt fasteners. Sure, I’ll probably keep it around in case I ever come across a spline fastener or 12pt one that my combination wrenches and 6pt sockets cannot handle. Or not, maybe I will give it away.
The Multi Wrench won’t easily round-off grade 5 or class 8.8 bolts, but it will likely do a number on softer lower quality bolts found in consumer goods and RTA (ready to assemble) equipment.
I cannot offer any recommendations based on these photos alone. As mentioned, a full hands-on review is in the works, and it will take a look at the Kobalt Multi Wrench as a whole.
What I can say is that separate SAE and metric spline/universal wrenches and sockets will fit fasteners better than than this tool can, 12pt tools will fit better than “universal” ones, and 6pt tools will fit even better.