Material guide
Bandknife blades for cutting foam
Foam is cut, not sawn. A honed bandknife edge parts PU, memory and rebond foams cleanly with no dust and no kerf loss, with toothed bandknives keeping the cut moving in denser grades.
The problem with cutting foam
Put a toothed bandsaw blade into a block of PU foam and the teeth do not cut it so much as tear it. Foam is soft, elastic and full of air, so it deflects around each tooth instead of shearing, then springs back torn. The result is a ragged face, a snowstorm of crumb and a kerf of material lost on every pass. On memory foam the problem is worse: the material grabs, compresses and recovers unevenly, leaving a wavy cut that scraps the piece.
The right tool is not a saw at all. A bandknife is a thin continuous knife edge (toothless or lightly toothed) honed sharp so it parts the cell structure in a single slice. On a toothless edge there is nothing for the foam to snag on, no dust and no kerf loss: the blade separates the block rather than machining a slot through it.
Edge profile then follows density. Soft PU foams slice cleanly on a straight edge, while rigid grades call for a scallop edge that bites in rather than skating over the surface, with wavy edges covering the densities between. At the top of the density range, lightly toothed bandknives bite into medium and high density foam that grips and drags on a plain edge.
Recommended blades for foam
No blade is listed in the shop for foam at the moment. If you cut it regularly, ask about it on the contact page.
Ask on the contact pageGetting the cut right
General rules that hold across machines. Exact widths, pitches and options are on each product page.
Match edge form to density
Foam density decides the edge profile. Soft PU foams part cleanly on a straight edge. Denser and rigid grades need a wavy or scallop edge that grips the surface and starts the cut instead of skating across it. If the face tears or the cut wanders, the edge form is usually wrong for the grade.
Keep the edge honed
A bandknife parts foam by sharpness, not force. As the edge dulls it starts to drag. Drag shows up as a torn face, crumb and a cut that wanders off line. Hone or regrind the edge as soon as the finish deteriorates rather than pushing on; a keen edge is the whole difference between slicing and tearing.
Let the knife do the work
Foam compresses under pressure, so forcing the feed squashes the block against the edge and the cut recovers wavy once the material springs back. Feed steadily and let the knife slice at its own pace. Memory foam in particular rewards a patient feed: rushing it distorts the block and the finished dimension with it.
Choose knife or wire
Straight slitting and splitting of blocks suits a wide bandknife. Tight contoured shapes in soft, rigid or memory foam call for a narrow CNC contour knife, while medium and high density grades want a lightly toothed edge that keeps the feed moving. Match the blade to the machine and the shape you are cutting, not just the material.
Industry guide
Foam, Insulation and Packaging Conversion
Cutting foam for a living? The industry guide maps the whole workload, not just this material.
Frequently asked questions
What blade do I need for cutting foam?
Can I cut memory foam with the same blade as ordinary foam?
Will one blade handle foam, insulation and packaging materials?
Tell the blade wizard your machine and length and it will narrow the range for foam.
Find my blade