Hex Keys

  • Klein Tools 70550: The Hex Set I Actually Carry

    BySteve

    Look, I’ve bought plenty of hex sets that ended up living in my bottom drawer. The Klein 70550? It’s been on my belt for two years straight.

    What sold me wasn’t the “heavy duty” marketing—it was the first time I folded out that extra-long 5/16″ key and actually reached a blower motor setscrew without pulling the whole unit. The SAE sizing covers about 90% of what I hit on residential calls, and the fold-up design means I’m not fishing loose keys out of my bag while balanced on a ladder.

    These aren’t the cheapest hex wrenches out there, but they’re Klein—which means when I crank down on a seized screw, something’s going to give, and it won’t be the tool. If you run service calls, you need keys you can count on. These are it.

  • Klein Tools BLS18 Hex Set: My Field-Tested Review

    BySteve

    I’ve put Klein’s BLS18 hex set through eight months of real-world HVAC work, and here’s the truth: these aren’t your average hex keys. The color-coding actually matters when you’re working in a dark attic or cramped crawlspace—no more squinting at tiny size markings. The long arm gives you serious leverage on those stubborn set screws on blower motors, while the ball end saves your sanity when you need to work at an angle on condensing units.

    What sold me? The heat-treated steel holds up to the torque we actually apply in the field. I’ve stripped cheaper sets on a single compressor job. At this price point, you’re getting both SAE and metric coverage without the premium Klein usually commands. They’re not indestructible, but they’re the first hex set I’ve actually wanted to keep in my bag.

  • My Take: Mutt Tools 17pc Folding Allen Key Set

    ByMike Izzo

    I’ve been turning wrenches on HVAC units for over a decade, and I can spot a gimmick from a mile away. This Mutt Tools 17-piece set isn’t one of them. The color-coding actually matters when you’re crammed in an attic with a headlamp, trying to grab the right size fast. The folding design keeps them compact in my bag without the jangling mess of loose keys. What really sold me is the durability—these handles haven’t stripped out like cheaper sets, even after months of daily use on condenser panels and blower assemblies. The size markings stay legible, which seems small until you’ve grabbed the wrong key three times in 95-degree heat. Are they perfect? No tool is. But for the price, they’ve earned a permanent spot in my kit.