HART Tools HLST051VNM 40V Carbon Fiber String Trimmer Review

HART 40V Brushless Carbon Fiber String Trimmer Review

HART Moves Up The Charts With Brushless Carbon Fiber String Trimmer

The best lawn mowers can make your overall lawn look fantastic—but you still need to trim and edge the areas where a mower can’t get to. Some of the best-rated string trimmers tend towards the heavy side and many DIY models don’t have the power to really get the job done. We got our hands on the HART Tools HLST051VNM 40V Carbon Fiber string trimmer which promised to perfectly balance power and ergonomics.

HART Tools HLST051VNM Features

The HART Tools HLST051VNM strong trimmer is attachment-capable using the company’s universal attachment connection. That means you can use it with any of the HART PowerFit attachments. With this string trimmer, the carbon fiber shaft really stands out and provides strength while reducing overall weight.

carbon fiber shaft

A 3-position detent on the power head gives you the ability to do something most power heads don’t: turn the string trimmer 90° for edging while maintaining your current grip. We love the ergonomics of this design decision—more manufacturers should consider this!

HART Tools HLST051VNM attachment point

HART Tools HLST051VNM 3-in-1 Bump Feed Head

The HART Tools HLST051VNM carbon fiber trimmer gives you a 3-in-1 trimmer head. It lets you flip the integrated cutter to choose between a more powerful 13-inch cut or a more productive 15-inch swath.

Beyond that, Hart Tools includes a second head with plastic grass-cutting blades. With more mass, these plastic blades can slice through thicker grass much more easily than even a standard 0.95-inch trimmer line. Use it sparingly for those really tough areas.

alternative trimmer head with plastic cutting blades

Balance and Weight

The HART Tools HLST051VNM 40V string trimmer weighs 8.8 pounds without the battery. Add in a 4.0Ah battery, and you bring that to around 11.1 pounds. We’ve used lighter string trimmer, but we’ve also used much heavier ones!

Since the motor and battery sit at the rear-oriented powerhead, you get a decidedly rear-weight distribution. We expect that with attachment-capable strong trimmers and it ends up working out well once you begin working with the tool.

Additional Highlights

  • Works with all HART Tools 40 batteries
  • 8+ PowerFit-compatible attachment options (snow thrower, brush cutter, cultivator, tiller, string trimmer, blower, hedge trimmer, edger, pole saw)

HART 40V Brushless Carbon Fiber String Trimmer Performance

This model rises above the HART Tools HLST061VNM string trimmer we reviewed earlier (and you certainly get more performance than with their 20V 13-inch trimmer). The fact that you can drive a 0.095-inch line and cut through even thicker grassy areas (of which we had a plethora) made this a confident tool to use. While not strong enough to take on truly dense stalks as we have at the ranch, it made quick work of Bahia, St. Augustine grass, and our accouterment of various weeds.

HART Tools HLST051VNM 40V strong trimmer

Vibration was manageable and not much lower than you find with comparable gas string trimmers. Premium products from higher-priced competitors do yield even less vibration—something to consider if that matters a lot to you.

For runtime, we managed to slap in a freshly-charged 4Ah battery and use this string trimmer for just under 30 minutes. That had us running the tool at High speed and loaded with 0.095-inch line for the 15-inch cutting swath. By our math, that should easily tackle yards up to 1/2-acre unless you have some seriously complex landscaping! If you do need to recharge the battery that comes with the HART Tools HLST051VNM kit, the included fast charger gets you back in the game 3X faster than the standard 40V charger.

HART 40V Brushless Carbon Fiber String Trimmer Price

You can find this HART string trimmer at Walmart in-store and online for $248. The kit includes the trimmer, 4.0Ah battery, and fast charger. HART Tools provides a 5-year tool warranty and 3-year battery warranty.

The Bottom Line

HART balances performance and weight very well with its 40V Brushless Carbon Fiber String Trimmer. It helps push HART’s outdoor power equipment line forward, signaling the brand is ready to reach homeowners that want higher-performing lawn care tools.


  • Model: HART HLST051VNM
  • Power Source: HART 40V battery
  • Cutting Swath: 13 – 15 inches
  • Max Line Diameter: 0.095-inch
  • Weight: 88.8 pounds bare, 11.1 pounds with 4.0Ah battery
  • Warranty: 5 years
  • Price: $248 kit with 4.0Ah battery and fast charger

Check out all of HART’s lawn and garden tools here .

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