Reinforced belting cover and dense gasket that need two-fisted stiffness — the .065" flexes; that's the flat .083" 60450/60510.
Thin cloth, webbing, and general fabric — the flat, livelier 60090 cuts those cleaner; a hollow grind is wasted and slightly more delicate on thin sheet.
Deep bun foam beyond ~4" — step to the 6" hollow blades (60720/60750).
Firm high-density foam wanting a rigid straight cut — the .083" hollow 60480.
And, like every square point, it is not a pry bar or scraper.
The cardinal rule of cutting foam by hand: a drawn slicing stroke cuts clean; downward pressure compresses and tears. Long strokes, the full edge, low pressure.
02
Compress a little at the line
Lightly compressing the foam at the cut both steadies it and lets the edge reach through more depth per stroke. Over-compress and the cut springs back oversized; find the light touch.
03
Keep it keen — foam punishes a dull edge more than anything
A sharp hollow-ground edge glides; a dull one drags, and drag in foam means torn, fuzzy cell walls and a wandering line. Hone often. When you re-sharpen, respect the hollow grind — sharpen the existing bevel; do not flatten the relief away on a coarse stone, or you turn a hollow-ground knife back into a flat wedge.
04
Maintain the high-carbon steel
Stone, strop, and wipe dry. Foam cutting is usually dry work, which is kind to carbon steel — but any humidity or damp foam still warrants a wipe.
Asked at the counter
BUYER QUESTIONS ANSWERED BEFORE THE CART, NOT AFTER THE RETURN
Why hollow ground?
The relief behind the edge keeps the blade from wedging and tearing in deep, dense material like foam; Hyde states it "works for cutting dense materials like foam."
60180 or 60480 for foam?
This .065" for softer, open-cell foam; the .083" 60480 for firm, high-density foam.
How thick a foam can it cut?
Up to roughly its 4" reach; for thicker bun foam use the 6" hollow blades (60720/60750).
Why not press straight down?
It compresses and tears the foam — always slice with a long stroke.
How do I sharpen a hollow-ground blade?
Follow the existing bevel; don't grind the hollow flat on a coarse stone.
