May 18, 2021

Professional Tool Reviews for Pros

CAT S42 MIL Spec Smartphone Review

CAT S42 rugged smartphone
PTR Review
  • Pro Review 7.5

The rugged CAT S42 smartphone giveth and taketh away. It offers a larger 5.5" screen than the S41 but sacrifices pixel resolution and density. It offers excellent runtime, but drops the battery size. It does, however, pass a tougher MIL-Spec 810H standard for tough jobsite use and abuse. And that might be the most important factor.

Overall Score 7.5 (out of 10)

We found the CAT S41 rugged smart phone a bit tougher than most. When they approached us to check out their newest jobsite-tough CAT S42, we wanted to see whether this MIL Spec smartphone upgrade really improved upon the original.

I’m not gonna lie—our office mostly uses iPhones for work. The cameras and functionality are difficult to beat—particularly when we all use iMacs for our day-to-day computing. It’s an ecosystem thing… In any case, iPhones are fragile. I don’t care how much they claim to have the latest Gorilla glass or waterproofing…have you seen one lately? Thin. Rounded. Dainty.

The CAT S42 suffers none of that. This phone seems made specifically for folks demanding a tough phone that can handle being dropped, kicked, dunked, or otherwise abused by the jobsite. It has the looks, specs, and reputation to stand up in the real world where—to quote Kenny in his review of the S41—“sexy smartphones are afraid to get their pretty little screens dirty.”

Can’t really say it better than that.

CAT S42 vs S41 Smartphone

Before we jump into anything specific to our use of the CAT 42 smartphone, let’s compare the CAT S42 vs the S41. Starting here lets us understand where to focus and why you may or may not want to opt for the newer model over the old one.

CAT 42CAT 41
Battery4200 mAh5000 mAh
Talk TimeUp to 38 hoursUp to 38 hours
Standby TimeUp to 44 daysUp to 44 days
Resolution1440 x 7201920 x 1080
Screen5.5″ Gorilla Glass 55″ Gorilla Glass 5
Rear Camera13 MP13 MP
Front Camera5 MP8 MP
Wi-Fi802.11 b/g/n802.11 b/g/n
ProcessorMT6761D Helio A20 Quad-core 1.8GHzMT6757 Helio P20 Octa-core 2.3GHz
GPUPowerVR GE8320Mali-T880MP2
Internal Memory32 GB32 GB
Micro SD Capacity2 TB2 TB
OSAndroid 10/11Android Nougat
IP RatingIP68IP68
Waterproof1.5 m for 35 min.2 m for 60 min.
MIL Spec810H810G
Drop Rating1.8 meters1.8 meters
Dimensions6.35 x 3.04 x 0.5 in5.98 x 2.95 x 0.5 in.
Weight0.485 lbs0.48 lbs

CAT Phones S42 Key Features

4,200 mAh Battery

The 4200 mAh battery on the CAT S42 will give you well over a day of use on the jobsite. The CAT S41 delivered 38 hours of talk time and 44 days on standby. Even though this phone has a smaller battery, it seems to use it well enough to maintain those numbers. A lot of that might be attributed to the power-sipping processor.

Defining Rugged

Like its predecessor, the CAT S42 carries a MIL SPEC rating—but with a 810H designation. Rather than an iterative update, the MIL SPEC 810H represents a more thorough testing procedure. In fact, the new spec includes 285 extra pages of testing procedures. As an example, 810G required a drop test onto 2-inches of plywood over concrete. The new 810H spec impact surface uses a steel plate on concrete. The CAT S42 services a 1.8m (6ft) drop onto that steel surface.

CAT expresses an IP68 rating for the S42 against water and dust ingress. That presumes at least some level of both underwater and high-pressure spray protection. The same glove- and wet-finger-friendly Corning Gorilla Glass 5 protects the screen. Together, I don’t believe there’s any question as to whether this phone should provide better protection on the jobsite than something like an iPhone 11—even with a protective case.

We thought the Kyocera DuraForce Pro impressed us with its ability to be submerged 2 meters for 30-minutes. The CAT S42, like the S41, lets you submerge the phone for up to an hour.

CAT S42 rugged smartphone waterproof
You can still catch Pro Tool Reviews Live, even underwater!

One disappointment is that this phone doesn’t offer wireless charging. That seems like the best way to achieve additional waterproofing capability. Even more, it maintains the use of a micro-USB port instead of the newer USB-C ports.

microUSB charging port

Understanding the CAT Phones S42

If you don’t understand the intended use of the CAT Phones S42 smartphone, you may focus on its rather lackluster specs. The MT6761D Helio A20 Quad-core 1.8GHz processor doesn’t stir the heart. The 1440×720 5.5-inch display won’t stun you with its lower-density pixels.

And that should drive you back to the design goal—ruggedness. This is a rugged phone. Go ahead, take it to the jobsite and toss it onto a bundle of lumber. Set it down on the ledge of a rafter while you work. It can take it.

Rear 15 megapixel camera

Onboard storage is 32 GB—the same as the S41. You can, however, add a micro SD card with up to 2 TB of additional storage. We really think 128 GB would make a huge improvement, however, it really depends on your jobsite needs. MicroSD cards also don’t cost much these days.

Operating System

The S42 runs on Android 10, and you can upgrade to Android 11 when it comes out. A shortcut on the home screen opens up tools from the Bullitt Group Toolbox, featuring helpful apps for generating quotes, measuring, invoicing, making calculations, and more.

Bullitt Group Toolbox


The CAT S42 uses the same resolution 13 MP main camera but swaps the 8 MP “selfie” camera of the S41 for a 5 MP model. All we care regarding cameras is picture quality…and we could care less about selfies. With that said, we took a couple of side-by-sides comparing the S42 with the default 1X lens on the iPhone 11 Pro Max. You may call that an “unfair fight” but it gives us a great point of reference.

Indoors, the iPhone 11 Pro Max generates a much warmer photo. It also has significantly more detail—which you can even see with the uploaded, compressed version of this photo. Notably, this interior photo had no artificial lighting, making it a particularly difficult photo to take. The S42 proves that it cam at least hold its own for interior shots when you need to document or detail anything that may not have a ton of ambient light present.

Taking a photo of a flower, the 13 MP camera of the CAT S42 does a reasonable job capturing depth and decent black levels. It just lacks the crispness of the iPhone.

Again, we see the same story, but certainly the CAT S42’s camera can take reasonably good photography to get the job done. As a jobsite phone, we see no difficulty using it to capture onsite proof photos for estimates and bids.


CAT maintains the left-side programmable button that works with push-to-talk if you use that technology. You still get no fingerprint reader on this model (you’ll have to upgrade to the S61 for that). Unlocking the phone requires a code or finger swipe pattern.

Notably, instead of using physical buttons for Android OS navigation (back, home, and overview) these now occupy virtual overlay space at the bottom of the screen. Volume and a textured power remain on the right side.

You get SD and dual-SIM card access on the left via another rubberized cover. We like that you can access these without having to open up the case. Lastly, a headphone jack is up top. That surprised us as Bluetooth is nearly ubiquitous, and a phone designed to be waterproof would do well to eliminate as many points of ingress as possible.

Audio/Video Playback

The screen does very well indoors, but like many LCD phone screens, dims a bit outside in the sun. It has an efficient Auto mode that manages brightness based on the ambient light. CAT dropped the screen resolution to just 1440 x 720 as well—lower than the S41’s 1920 x 1080. At the same time, they increased screen size to 5.5″. The net result is you get a larger screen with a lower pixel density.

Sounds come across loud and clear with this phone—stunningly well, in fact. Phone calls set to speaker sounded clear (and the headset modes worked great as well). Overall, you get nice clear playback of both music and voice, though the bass response is lacking. Bluetooth functioned well with the phone and we paired a set of ISOtunes FREE earphones with them for hands-free talking and music.

Currently, the CAT S42 works with any GSM provider. Verizon, Sprint, and U.S. Cellular use CDMA and are not compatible with CAT phones. Keep that in mind as you shop.

The Bottom Line

The ~$299 CAT S42 clearly emphasizes durability over class-leading performance and features. If you compare it to the big-dogs costing twice as much you could come away disappointed. What you get, however, is durability, run-time, and excellent value.

Those looking for a slim and sexy phone won’t come away impressed. Those looking for a true jobsite phone, however, may come away wondering why they haven’t tried CAT Phones before. If you want a tough phone that can actually stand up to being dropped, tossed, kicked, and manhandled—give the CAT S42 a serious look. In fact, the only real question might be whether to get this or the older S41 before it sells out. It makes for an equally-compelling solution at a slightly lower price point.

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