Klein Tools DK06 Duct Knife: My Go-To Blade
I’ve been running HVAC calls for over a decade, and I’ve gone through more duct knives than I care to count. Most either dull out after a few jobs or feel like they’re going to snap in half when you’re wrestling with dense board. The Klein Tools DK06 changed that for me. This thing cuts through flex duct like it’s not even there, and when you hit rigid board, the serrated blade actually grabs instead of sliding off. The grip doesn’t get slippery when your hands are sweaty, and at the end of a long day, my hand isn’t cramping up. I keep mine on my belt in the included sheath, and it’s held up to daily abuse for two years now. It’s not the cheapest option out there, but it’s the last duct knife I’ve had to buy.