Hercules SC-190 SC-590 SC-890 Hot Knife Replacement Blades - 3" Stamped Steel Flat Blades for Foam Cutting Tools - Compatible with Most Styrofoam Heat Cutters - Perfect for Crafting, Packaging Insulation & DIY Projects

used it to cut polystyrene insulation for my barn. worked like a champ. be aware that it can get HOT on the high setting. the blades that come with the knife are good too. other brand blades also fit. AND I do believe I will be making some soldering iron tips for this unit. The price is great too. Do not waste your time with the ultra cheap hot knives with a fat non replaceable blade. I tried 3. was lucky to make 15 cuts ( letting the blade cool between cuts)before the heating element burns out and/or the switch burns out. Buy this knife instead. it is great.