Everhard DA71000 - Klenk Dual Duct Knife - Wood Handle

Tough, balanced, and purpose-built for HVAC work, the Klenk Dual Duct Knife pairs a thick, stainless blade with a classic rosewood handle so you can sweep through duct board, flex-duct, and insulation with control. One edge is serrated for aggressive cuts; the other is smooth for scoring and finishing—so you get fast starts and clean lines without swapping tools. A slim, reinforced ripstop sheath rides on your belt for easy access between cuts.

Key Features

• Dual-edge 3 mm stainless blade — serrated on one side, smooth on the other, giving you both fast bite and clean finishing in a single tool. Heavier/thicker than many look-alikes for better stability. 
• Cuts common HVAC materials — designed for duct board, flex-duct, and insulation; smooth
• Rosewood handle with brass rivets — durable, comfortable, and easy to index in the hand. 
• Slim, reinforced ripstop nylon sheath — belt-hang design keeps the knife protected and always at hand on the roof or in the attic.
• 11″ overall length — a practical reach for long strokes while staying maneuverable in tight spots.

Blade:

• 3 mm thick stainless steel
• One smooth edge for clean cuts on duct board
• One serrated edge for slicing through flex duct and insulation 

Handle: Classic rosewood handle with brass rivets for a traditional, durable grip 

Sheath: Includes a slim, reinforced Ripstop nylon sheath with belt loop for convenient carrying 

Overall Length: Approximately 11″ (28 cm) 

Weight: ~0.48 lb (0.22 kg) 

Construction: Made in the USA, known for durability

• Hold the knife securely by the rosewood handle.
• Select which blade edge to use (serrated or smooth) based on material (e.g. insulation, duct board).
• Insert the blade into the material at a slight angle.
• Draw the knife smoothly through the material, applying steady pressure.
• If cutting thicker or dense material, repeat or use both edges as needed.
• After cutting, wipe the blade clean of debris or insulation fibers.
• Return the knife to its ripstop nylon sheath and store in a dry place.

Q: What materials is this knife designed to cut?
A: Duct board, flex-duct, and insulation. Use the smooth edge for clean scoring and trimming on duct board/foam; use the serrated edge to bite through fiberglass and flexible duct layers.

Q: What’s the benefit of having both smooth and serrated edges?
A: The smooth edge makes straight, clean cuts and precise scores; the serrated edge delivers fast, controlled slicing through tougher, fibrous materials—so you don’t have to switch tools mid-task.

Q: Can the blade be resharpened?
A: Yes. Lightly hone the smooth edge with a fine stone or file, and use a suitable sharpening tool for the serrations. Avoid overheating; wipe clean and lightly oil after sharpening.

Q: What are the size, weight, and carry details?
A: It’s approximately 11″ (28 cm) overall and about 0.48 lb (0.22 kg). It includes a slim, reinforced ripstop nylon sheath with a belt loop for convenient carry between cuts.