For me, few things are as exciting as the first moments you spend with a highly-anticipated new tool. Would it perform as well in-house as the demonstrations and previews we witnessed? Would it help us get work done faster, or with more efficiency or capacity? As Christmas rolled around this year, the Bosch CM12SD 12″ Miter Saw was scheduled to arrive just prior—along with the very capable Bosch T4B miter saw stand.
Christmas morning was going to be a bit more complicated if I didn’t get that saw calibrated, and the stand put together, early enough. I was eager to test this new flagship saw from Bosch, and if I didn’t set it up before Christmas day, I’d spend most of the morning hoping everyone would hurry up so I could get out to the shop and get started. As it turns out, the Bosch CM12SD miter saw did get here in time to allow me to thoroughly enjoy Christmas with my extended family and avoid any outward appearance of a psychological conflict. After admitting all that, I feel like I may have an addiction that requires professional help. Still, Bosch’s new flagship CM12SD miter saw had been on my list since we saw it introduced at the 2015 World of Concrete last year.
Shameless plug alert! We’re headed back to Las Vegas at the beginning of February for this year’s show, so be on the lookout for live coverage on Facebook and Twitter!
Bosch CM12SD 12″ Miter Saw Specifications
- Motor: 15 amps
- Blade Size: 12″
- No Load Speed: 4000 RPM
- Miter Range: 52 degrees left, 60 degrees right
- Miter Stops: 0, 15, 22.5, 31.6, 45 degrees left/right, 60 degrees right
- Bevel Range: 47 degrees left and right
- Bevel Stops: 0, 22.5, 31.6, 45, 47 degrees left and right
- Weight: 65 pounds
- Warranty: 1 year
- Price: $649
The Big Deal About the Bosch CM12SD Miter Saw
Professional power tool brands don’t come out with miter saws as often as they do cordless drills and impact drivers. They’re a higher price point tool and not much changes from one year to the next. The Bosch 12-inch Axial Glide miter saw (GCM12SD) is several years old, but it’s nowhere near out of the game. We did a compact miter saw shootout for example, and you can expect most of these models to have at least a 5 or 6 year shelf life.
To be effective, a 12″ miter saw has to be two things above all else: accurate and powerful. After that, look at the smoothness of cut and the beveling capabilities. If you’re one of the companies that have managed to figure it out, you just don’t change it up often. From there, the changes become more subtle as they try to improve the limitations of a miter saw.
Bosch tackled the issue of vertical clearance with this model in an effort to really push the value for trim carpenters installing larger crown molding. They moved the motor a little bit in order to create more clearance. They also added a crown molding chop lock stop (say that three times fast!). This feature simply swings into place to stop the slide at the exact position offering the most clearance for cutting crown. Lock the slides once you’re against it, and you have 6-1/2″ nested crown cutting capacity and 6-3/4″ base capacity against the fence.
There’s More, Right?
I’m a perfectionist—watching me try to eliminate variables in a shootout can be painful to watch. The Bosch CM12SD came out of the box in pretty good shape. The miter and right bevel were each about 1/4 of a degree off. 15 minutes later they were as perfect as my Empire Level rafter square with each point of the blade in perfect unison with the edge.
Miter adjustments haven’t really changed. Positive stops on all the popular angles are solid and easy to find. At 0 degrees, this Bosch 12″ compound sliding miter saw offers 4 x 14 dimensional cutting capacity. Miter over to 45 degrees, and you’ll still have enough room to cleanly cut through a 4×10.
Thankfully, Bosch hasn’t messed with their bevel lock. It’s one of the few that are on the side of the saw within easy reach. One of the relatively new features (and completely new on this 12″ saw) is the rotating turret bevel stop (there’s one on each side). Rather than having a mechanism slip into a detent like the miter stops, you simply twist the bevel stop to the degree you need it on either side. On the right, you’ll need to pull a plate back that acts as the 0 degree stop in order to continue your bevel.
Bevel capacity is 47 degrees to both sides. Those bevel stops are going to be found at 22.5, 33.9, 45, and 47 degrees. You want to be sure and calibrate both sides. Adjustments are made using a bolt with a lock nut. It can be a little tricky to dial it in perfectly. Getting the lock nut to tighten back up without moving the bolt requires some finesse.
Bosch CM12SD Performance
The Bosch CM12SD is like most 12″ miter saws on the market—it has a 15 amp belt-driven motor. As I made a few test cuts on 2×10 and 4×4 pressure-treated pine, the motor slowed down a little bit, particularly on bevel and compound cuts. It’s similar to my experience with other belt-driven miter saws, and there is a difference with those compared to models that use a direct drive motor. We also don’t use a Variac to control the voltage output in our testing, so voltage drop may also affect the results. You’ll also see cut efficiency increase with a thinner kerf blade due to the lower physical resistance.
The Bosch CMD12SD motor is certainly powerful enough to make any cuts you’re likely to come across. The stock blade is solid, but there are better 12-inch thin kerf miter saw blades out there if you want to upgrade. If you’re doing general construction, the stock blade will work fine, and the quality of the cut was good for basic trim work.
The 4-3/4″ fences provide excellent support for a wide range of material lengths, including the crown molding that this saw is designed to maximize. A pair of base extensions offer support up to 40 inches. I found they stick a bit in the closed position, though slide easily enough once you get them out. I thought they might need a little oil, but there was already some on it. Perhaps it will loosen up over time. Regardless, these extensions are a welcome addition if you aren’t planning on using a miter stand.
Most miter saws should be solid in the accuracy department on miter cuts. Things tend to get a little dicier on bevel and compound cuts though. Tilting the motor head can introduce a slight blade wobble or even a flex in the rails resulting in some belly on your finished work. As expected, the Bosch CM12SD was perfect in all the miter cuts I performed and even on the bevel cuts as well. I found just the slightest touch of belly on a 45-degree bevel, 31.6-degree miter compound cut—possibly to the tune of 1/64 inch. It’s doubtful it would show on a finished product.
One thing Bosch does well that other miter saws often gloss over is on the positive miter stops. If you don’t have the override lever engaged, you’re going to slip into the next miter stop you come across and go no further. This isn’t the case in other saws that allow you to kind of click-and-go over the top of the stops if you’re quick enough. It’s not a make or break kind of issue, but it does promote confidence in Bosch’s build quality.
The depth of cut adjustment offers a nice range for dado and other non-through cuts. With the 12″ blade, I was able to get a maximum of 3-15/16″ above the base. It’s a screw-based adjustment, so there are effectively infinite positions down from there.
Dust collection was a little disappointing on this model from Bosch. Their compact miter saw was so good in this category, but the latest 12″ model struggled.
Ergonomically, the Bosch CM12SD is a monster saw. Its weight can be attributed to the amount of steel used in the design, which is a great thing from a build quality standpoint. I’d highly recommend the Bosch T4B miter saw stand if you want to haul this saw around to and from job sites. The gravity rise stand is one of the best designs we’ve ever seen. Its wide wheelbase keeps your saw from wanting to tip over when transporting it across uneven ground, and it fits perfectly in a small enclosed trailer or in the back of a truck. The built-in extensions also require no ground supports thanks to their inherent rigidity—that makes them very quick to use. Given the fact that you can collapse and deploy it from a standing position, your back will thank you every time you use it.
Ergonomically, there’s a slight feeling of fighting the tool as you push the motor head down and begin your cut. That has to do with the height of the handle and trigger. I’d like to see the next generation have that rotated around the front in a lower position to alleviate some of that feeling. As it stands now, it’s a lot like driving a custom bike with ape hangers—and, yes, that may actually appeal to some!
Final Thoughts
With dust collection and a slight change to the handle height as my only suggestions for improvement, it’s easy to recommend the Bosch CM12SD 12″ miter saw to any professional. You’ll get the power you’re used to (and maybe more) compared to the other 15 amp saws. Where this model from Bosch really stands out is in its build quality, accuracy, and deep cut capacity.
Trim and finish carpenters will love the extended vertical capacity dialed in by the crown molding stop on the rails. The accuracy is high enough to keep woodworkers happy with it as a shop saw. Whether you’ve got this saw bolted to a workbench or plan to drag it around the job site, it’s built to last. With regular cleanup and maintenance, the Bosch CM12SD gives all indications that you’ll get plenty of years of reliable use out of this saw.
