Over the last few years, Flex has built its reputation by developing high-performance cordless tools that challenge the established leaders. We recently got our hands on the FX1352 impact driver, but rather than pushing a higher benchmark, it’s aiming for a different target.
I’ll walk you through what I learned from using this impact driver, show you how it performed in our tests, and help you see where it fits in Flex’s overall impact driver portfolio.
Pros
- Confident driving power
- Self-tapping screw mode
- Full feature set
- Ergonomic design
- Adjustable LED brightness
- Excellent kit value
Cons
- Not as strong as top-tier performers
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Flex FX1352 Impact Driver Performance
Speed and Power
At its heart, the Flex FX1352 houses a brushless motor that produces up to 1,900 in-lbs (158 ft-lbs) of torque, 3,500 RPM, and 4,500 IPM. Those are strong numbers for an impact driver in this class, and put it squarely in the conversation as an everyday-use kind of tool. Flex also equips this tool with three speed settings and a self-tapping screw mode, allowing you to tailor performance to the task at hand.
For driving deck screws, cabinet hardware, medium lag bolts, and structural fasteners, there’s plenty of muscle on tap. The high top speed should translate into quick driving performance, while the lower speed settings offer more control when working with smaller fasteners or delicate materials.
Self-Tapping Mode
One feature that stands out is FLEX’s dedicated Self-Tapping Mode. Rather than simply relying on trigger control, the tool automatically adjusts speed when driving self-tapping screws into metal. This helps prevent stripped fasteners, broken screw heads, and overdriving. It’s a feature we’ve seen on several Flex impact drivers over the years, and it’s a welcome addition here.
Hands-On Impressions
Based on its power output and speed, the FX1352 is in that sweet spot between compact installation drivers and full-blown heavy-duty fastening tools. While it won’t match the brute force of FLEX’s flagship 2,500 in-lb Quick Eject model, many folks may actually prefer this setup because it offers a little more finesse while still delivering more than enough power for everyday construction, remodeling, electrical, HVAC, and woodworking applications.
For testing, I ran this impact driver through two of our standard impact driver tests.
RSS Screw Test
The first fastening test falls squarely into the medium-duty category. For this evaluation, we drive three 3/8-inch x 8-inch GRK Fasteners Rugged Structural Screws (RSS) flush into stacked and glued OSB subflooring. To ensure consistency, we use a 2-inch pilot hole to start each fastener straight and then average the results from all three runs.
While this test isn’t nearly as demanding as our heavy-duty fastening challenges, it’s also far more involved than driving standard deck screws. Success here isn’t determined solely by raw speed or impact rate. Instead, this application rewards tools that strike the right balance between speed, torque, and overall efficiency.
In this test, the FX1352 averaged 16.7 seconds across the three runs. This is notably slower than Flex’s flagship FX1371, which posted a time of 5.86 seconds. But remember, Flex isn’t chasing top-tier performance with this model, and there is a significant difference in max torque between the two.
In real-world applications, the Flex FX1352 can handle this type of work, but if time is of the essence, this might not be the right model for you.
Bolt Break Test
For our next evaluation, we move over to the bolt-break test. Using our dedicated test rig, we torque eight 1-1/4-inch lug nuts onto matching 1-1/8-inch semi-truck studs to exactly 150 ft-lbs (1,800 in-lbs) using a digital torque wrench. From there, we use the impact driver to remove all eight fasteners and record the total time required to complete the test, averaging the results across the full run.
Although these are the same heavy-duty lug nuts we use when testing impact wrenches, the applied torque is significantly lower. At 1,800 in-lbs, the challenge falls comfortably within the rated capabilities of every impact driver in our test group. Rather than highlighting outright torque advantages, this test helps reveal how efficiently each tool converts its available power into real-world fastening performance.
Here, Flex posted a total time of 60.44 seconds. This is where the FX1352 really had to put in some work. For perspective, the FX1371 has 2,500 in-lbs of torque and finished with a total time of 13.98 seconds. The FX1352’s torque peaks at 1,900 in-lbs (158 ft-lbs), which is right on the limit of what this test requires.
While I was able to get through all eight bolts, I could tell that the tool was struggling towards the end. I think this is a case of “yes, it can, but it’s not ideal”. Given its power level, average pickup truck lug nuts are well within reach, but going beyond that threshold is dicey. Admittedly, our bolt rig is a tough proving ground for this tool class, but I’m happy to report that Flex made it through unphased.
Flex FX1352 Impact Driver Design Notes
Size and Weight
The FX1352 hits a nice middle ground when discussing weight. This impact driver clocks in at a respectable 2.4 pounds as a bare tool, 3.7 pounds with the kitted 2.5 Ah battery, and the head is only 4.4 inches from front to back. While it’s not branded as a compact model, these specs certainly put it in that neighborhood.
Ergonomics
The overall feel of the FX1352 is very familiar. You have Flex’s iconic rubber overmolding covering the grip as well as a few rubber bumpers across the tool body and head for added protection.
I really like the balance of this tool, and I’m glad they paired it with a 2.5Ah battery. This configuration is very easy to maneuver, and its small profile lets you access tight spaces with ease.
LED Ring Light
One new feature on this impact driver is the diffused LED ring light surrounding the collet. This is a big improvement over a foot-mounted light and provides better illumination on your bits and fasteners.
While the ring light is cool by itself, you can also adjust the brightness setting! To do this, press and hold the drive-control and M button for three seconds until the four LED mode indicator lights begin to blink. Then, press the trigger to cycle through the settings. There are five brightness settings, or you can deactivate the light altogether. When you’re all set, press either of the mode buttons to exit the adjustment settings.
Quick Collet
Flex equipped this impact driver with a quick-insert collet that allows you to push bits directly into the collet without pulling back on the collar.
Additionally, the spring-loaded mechanism ejects bits when the collar is pulled forward. These may seem like small details, but after dozens of bit changes throughout a workday, convenience features like this start to matter.
Additional Features
- Belt Hook and Bit Holder: These accessories fit on either side of the tool for added convenience
- Tether Ready: Easily affix a lanyard to the tool when working at height
Quick Model Comparison
As of right now, Flex has three impact drivers in their 24V lineup. While their designs are very similar, there are a few key differences in terms of overall power level and feature sets. Here’s a quick breakdown so you can decide which model is right for you:
| FX1352 (This model) | FX1371 (Flagship) | FX1331 (Compact) | |
|---|---|---|---|
| No-Load Speed | Mode 1: 1,500 RPM Mode 2: 2,300 RPM Mode 3: 3,500 RPM | Mode 1: 1,900 RPM Mode 2: 2,700 RPM Mode 3: 4,000 RPM | Mode 1: 1,300 RPM Mode 2: 3,000 RPM |
| Impact Rate | Mode 1: 2,800 IPM Mode 2: 4,300 IPM Mode 3: 4,500 IPM | Mode 1: 1,300 IPM Mode 2: 3,600 IPM Mode 3: 4,450 IPM | Mode 1: 3,800 IPM Mode 2: 3,800 IPM |
| Max Torque | 1,900 in-lbs | 2,500 in-lbs | 1,700 in-lbs |
| Head Length | 4.4 in. | 4.75 in. | 5 in. |
| Bare Weight | 2.4 lbs | 2.8 lbs | 2.0 lbs |
| Working Weight | 3.7 lbs (with 2.5Ah battery) | 4.9 lbs (with 5.0Ah battery) | 3.4 lbs (with 2.5Ah battery) |
| Price | $199 (kit) | $279 (kit) | $149.99 (kit) |
Flex FX1352 Impact Driver Price
The Flex FX1352 impact driver retails for $199 as a kit and includes two 2.5Ah batteries, a 75W charger, and a storage bag. Flex backs this impact driver with a 5-year limited warranty.
Should You Buy It?
The Flex FX1352 is a strong option for anyone looking for an everyday impact driver that trades off top-tier performance for a more compact size and lighter weight, but doesn’t feel underpowered. It delivers enough speed and torque to handle the vast majority of common fastening tasks while maintaining a lightweight, easy-to-control package.
On the Pro side, I think this is a great option for electricians, MRO techs, and HVAC Pros. Even GC’s may prefer it over Flex’s heavier flagship model for everyday driving.
On the other hand, Flex also makes a compelling case for the average Joe. This kit comes with two batteries and a charger, making it an excellent value if you want Pro quality for your home projects.
Specs
- Model: Flex FX1352
- Power Source: Flex 24V battery
- No-Load Speed: 0-1,500 / 2,300 / 3,500 RPM
- Impact Rate: 0-2,800 / 4,300 / 4,500 IPM
- Max Torque: 1,900 in-lbs
- Collet: 1/4 in. hex
- Weight: 2.4 lbs (bare tool), 3.7 lbs (with 2.5Ah battery)
- Head Length: 4.4 in.
