Reviewed October 2011

I am a self-confessed power tool junkie, I will happily admit... However, I can also appreciate a good, manual, non-electric hand tool when I see, or more importantly, use one. Of course, there are some tools that just cannot be motorized or computerized and the M.Power 3D Tri Square is one such tool.

Measuring and marking is usually one of the first steps to the actual construction of almost anything made of anything! As woodworkers, we are constantly measuring and marking parts of our projects before attacking them with sharp hand tools or power tools. Accuracy in measurement is crucial to result in well fitting joints, or for machining the correctly sized components. The old adage, "Measure Twice, Cut Once" is certainly appropriate when looking at a product like this.

M.Power Combination 3D Tri Square & Marking Gauge
The "3D" part of the tool's name comes about because the tool can be used as a marking gauge in three dimensions, the X, Y and Z axes. The z axis of measurement comes about because of the extended stock length of one side to provide a traditional saddle square function to the tool.

The "stock" of the tool, that is, the main body, is constructed from aluminium and machined on its reference face in a radial fashion. While the machined face is not super smooth in itself, it is consistent and is ground flat for all intent and purpose as a a reference edge to ensure accuracy. The stock is actually a two-piece construction. The main blade is clamped between the two parts of the stock with a mortise and tenon style joint which is then secured by screws. The advantage here is that the blade is securely clamped in the stock for accuracy, however, should damage occur to the blade or the tool be dropped and the main blade is no longer square to the stock, the blade can be re-aligned accurately, or if necessary, the blade replaced without replacing the whole square. Traditional squares may be set with no adjustment available, which might be great as accuracy is always retained (assuming it was accurate to begin with) but if the square is dropped or damaged and the square no longer measures square, no adjustment is readily available and in most cases the tool must be discarded and replaced in full (usually the cheaper option than to repair).

Using the M.Power 3D Combination Square in the traditional way

The main blade is constructed of Sheffield steel and is marked in both imperial and metric divisions. In fact, the markings are not marks, but indeed are laser etched for accuracy and precision. The blade has a measuring capacity of 9 inches and is 2 inches wide. The scale is zeroed precisely at the stock so quick and accurate measurements from the stock's edge can be made with ease. The other advantage here is that you can mark a square line of precise length too from the stock face or readily determine the thickness of any material up to 9 inches thick, or the width of a face up to 9 inches wide. The square is aligned to engineer's square standards. The accuracy out of the package is defined as within 0.001 degrees of square. I haven't the tools to test this accuracy but the quick and dirty test of marking lines using one side of the blade and flipping it over and matching lines with a second mark over the 9" available width appeared dead on. So while I can't confirm it is accurate to within 1/100th of a degree, I can certainly say it doesn't appear to be way out of square so it likely is close to that accuracy mark. For woodworking use it is, of course, more than accurate enough as there are very few cutting machines that can be dialed in with anywhere near the level of accuracy offered here.

I just wanted to mention a little more about the usefulness of the saddle square feature. The 2" deep stock component matched with the 9" wide blade allows for extra flexibility when using the 3D Try Square as a saddle square. Most saddle squares have 2" capacity in both planes but with the 9" blade, the M.Power 3D square allows accurate square marking on particular items like wide moldings that have rounded edges. The 9" wide blade allows accurate marking right across the face of most moldings, while the 2" deep saddle allows accurate reference against moldings or materials with rounded edges, meaning the saddle part of the square can rest securely against the widest point of any round or rounded shape, where most traditional squares with thin stock thickness don't have the depth capacity to perform such tasks.

It functions as a full 2" depth saddle square too.

On the end of the stock is a retractable angle setting blade/bevel gauge. This pivots around its fixing point and can be locked in any position with the locking clamp lever shown in the accompanying photos. Common angles are marked on the gauge (15, 30, 45, 60 and 90 degrees) although setting the gauge to an angle can only be done with an accuracy determined by how well you can visually align the angle line markings to the butt of the stock. You can also align to the reference face of the stock, but there is a small gap between the marked lines on the gauge and the edge of the stock face so there is more guess work involved. It's best to use the bevel gauge more as a rough guide than as an accurate tool. It would certainly be good enough for hand cuts, but if your require engineer's accuracy here then it would be best to try a more accurate bevel setting tool I would think.

While it is probably more accurate to mark on the reverse side of the angle,
it can also be done this way as well.

The other notable feature of this combination square is the adjustable pencil marking gauge which will allow you to scribe a parallel line along a workpiece. Just insert the supplied round pencil, or any standard pencil, secure it using the small screw in the holder and set the pencil to a mark, or if the pencil is properly sharpened and set in the holder at the right distance, you can use the inside edge of the pencil holder clamp component to measure off. A sharp pencil is the key here to consistency, and your accuracy will be greater too with a thinner scribed line. You could also use some kind of sharpened metal marking tool too if you can easily secure it in the holder. The blade of the square does sit up off the surface when the marking gauge is in use, and it does make the whole square a little more difficult to glide across a face or keep hard up against a reference edge of the material being marked, but it's not a deal breaker in my opinion, but worth mentioning in course.

Marking gauge attachment with scribed line

Another nice feature I should note is that with the bevel gauge extended to 90 degrees, the whole combo square can rest hard up against an edge of a workpiece and not fall off. With most combo squares, if you don't hold it there, it will likely instantly fall and hit something and damage the tool. While I still don't encourage that you leave the 3D combination square resting on the edge of any material being marked, it is a good idea to always have that bevel gauge extended to help protect the tool in case you do take your hand off it at any stage in the marking process. Note, however, that if the marking gauge attachment is installed on the blade and is located near the stock end, then the gauge will not hold to the edge.

That pretty much sums up the features. Use of the tool is pretty intuitive so I am not going to go into how to use the tool in detail. This is basic marking stuff and if you don't know how to use a marking gauge, I dare suggest you don't pick up any power tools or cutting tools just yet!

The retail price of around US$49 at time of writing is about right for this tool. It offers high levels of accuracy as a square and saddle square. The marking gauge is a handy feature that works well and is easily removed for regular square marking. While the bevel gauge depends on the user for accuracy, it provides a sufficient marking guide for most woodworking angle measuring applications. The large, wide blade affords the whole tool good stability in use. While the tool may not be perfect in every department, it is very usable and one of the better multi-function squares currently on the market, and perhaps the best in its price range.

M.Power 3D Combo Square & Marking Gauge Photos
All photos copyright onlinetoolreviews.com - unless otherwise indicated. Use without prior written permission prohibited

The M.Power 3D Combination Square

The bevel gauge locking feature

Here the bevel gauge is set at 60 degrees and locked in

The stock with flat machined reference faces

The marking gauge attachment installed

Marking gauge with pencil added, and ready to go.