Magrupak — Corrugated Box Flute Guide | magrupak.com
Thickness in millimetres, flutes per foot and flutes per metre for A, B, C, E and F flute.
A flute measures 4.8 mm at 33 ± 3 flutes per foot, which converts to 108 ± 10 flutes per metre. It is the deepest of the five standard US flutes and gives the most cushioning between the liners.
B flute is 3.2 mm at 47 ± 3 flutes per foot, 154 ± 10 per metre. C flute is 4.0 mm at 39 ± 3 per foot, 128 ± 10 per metre. The two sit close together in use: B is thinner with a higher flute count, C is deeper with a lower count.
E flute measures 1.6 mm at 90 ± 4 flutes per foot, 295 ± 13 per metre. F flute is 0.8 mm at 125 ± 4 per foot, 420 ± 13 per metre. At these counts the outer liner behaves close to a flat sheet, which is why retail print is set on E or F.
On narrow screens, swipe or scroll the plate sideways.
The tolerance on each count is part of the figure. A reading of 33 ± 3 flutes per foot means 30 to 36 flutes per foot is inside specification; the same logic applies to 47 ± 3, 39 ± 3, 90 ± 4 and 125 ± 4.
Thickness and flute count move in opposite directions across the set: as the flute gets thinner, the number of flutes per foot rises. Comparing two boards therefore means reading both columns, not just the millimetre value.
The metric flute counts per metre are derived from the per-foot figures and are given for readers working in grams per square metre and millimetres rather than pounds and feet.
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