B flute vs BC double wall: side-by-side numbers
BC double wall is 125% thicker than B flute (0.281 vs 0.125 in nominal). At the same ECT, the McKee formula rates a BC double wall box 50% stronger in compression; the trade is in size, crush resistance and print surface.
Side by side
BC double wall is 0.156 in thicker than B flute. On a 12 × 10 × 8 in box that makes the outside 0.31 in longer and wider and 0.47 in deeper, and at the same ECT the McKee estimate for B flute is 67% of the BC double wall figure.
| B flute | BC double wall | |
|---|---|---|
| Walls | single | double |
| Nominal caliper, in | 0.125 | 0.2813 |
| Flutes per foot | 47 | — |
| OD added to L and W, in | 0.25 | 0.563 |
| OD added to depth, in | 0.375 | 0.844 |
| McKee strength index, same ECT | 35.4 | 53 |
Same box, both boards
| Inside, in | BCT at 44 ECT, B | BCT at 44 ECT, BC | Boxes per pallet, B | Boxes per pallet, BC |
|---|---|---|---|---|
| 10 × 8 × 6 | 548 | 822 | 144 | 119 |
| 16 × 12 × 10 | 683 | 1,025 | 40 | 40 |
| 24 × 18 × 18 | 837 | 1,255 | 6 | 6 |
44 ECT is used on both sides only to isolate thickness; in practice the two boards are made to different grades. Pallet: 48 × 40, loaded to 60 in, column stacked.
Where each fits
B flute
- Thinner than C, so a lower McKee estimate at the same ECT
- More flutes per foot give better crush and puncture resistance
- A good surface for printing and for die-cut styles
BC double wall
- Nearly twice the caliper of C, so much stronger in McKee at the same ECT
- Heavier and bulkier: more board weight and larger outside dimensions
- The B ply on one face gives a better print or wear surface
Sources
- Foster, G. (1997). "Boxes, Corrugated." In Brody & Marsh (eds.), The Wiley Encyclopedia of Packaging Technology, 2nd ed. Wiley. ISBN 0-471-06397-5 (table reproduced in Wikipedia, "Corrugated fiberboard")
- Packaging Corporation of America: Profiles with a purpose
- McKee, Gander & Wachuta (1963), Paperboard Packaging 48(8)
Last reviewed . See all sources and how Packgent computes.