Dexter-Russell 5.5″ Scalloped Insulation Knife is a 5.5-inch scalloped serrated insulation knife — sized for batt insulation, fiberglass, and rockwool cuts in confined cavities (between joists, in attic bays). Dexter blades are forged from high-carbon stainless or DEXSTEEL alloy and individually ground on the bevel — meaning each blade gets a final sharpening pass by hand rather than coming off a stamping machine. The NSF certification on commercial models tracks the food-safe handle materials and ease-of-cleaning standard.
This works for tighter cavity cuts than the 8-inch can reach — wall cavities, attic flutes, rim joists, and floor-cavity batts. Dexter-Russell knives are the trade-default in American foodservice — diners, butcher shops, fish markets, pizzerias, bakeries, and commercial kitchens have run them for generations. The blades resharpen well, the handles don’t loosen, and the steel holds an edge through restaurant-volume use.
Dexter-Russell has manufactured commercial cutlery in Southbridge, Massachusetts since 1818 — the oldest continuous American cutlery manufacturer. The catalog covers SANI-SAFE plastic-handle commercial knives, Traditional rosewood-handle chef knives, Basics, V-Lo, iCut-PRO, and specialty profiles (pizza cutters, fillet knives, bread slicers, dough scrapers, insulation knives, hamburger turners). Made in USA.
