packgent

FEFCO 0206: Center special full overlap container (SFF)

The center special full overlap combines the two ideas: inner flaps meet in the center, and the outer flaps run the full width so they overlap completely. Each closed end carries a full inner layer and two full outer layers.

Dieline

53.25 blankL 18W 8H 889outerouterLinnerinnerWLWtab
Drawn by Packgent from the style's flap rule. Solid lines are cuts, dashed lines are scores.

Try your size. Inside dimensions in inches; the drawing redraws as you type.

Construction

  • Inner flaps are L ÷ 2 and close edge to edge.
  • Outer flaps are W long and overlap across the full width.
  • Whichever flap pair is longer sets the blank width: the inner pair when L is more than twice W, the outer pair otherwise.
Flap and panel rule
PartSize
Inner flapsL ÷ 2
Outer flapsW

Closure. Glue or staple through the outer layers; tape is optional.

Blank size

Nominal blank width is H + the longer of L (from two L ÷ 2 inner flaps) and 2W (from two W outer flaps).

Worked example at 18 × 8 × 8 in inside
BoardNominal blank, inWith allowances, inArea, ft²
B flute53.25 × 2653.75 × 26.259.8
C flute53.25 × 2653.88 × 26.319.84
BC double wall53.25 × 2654.38 × 26.5610.03

Allowances add one caliper per vertical score and per flap score. Your box maker sets the real scores. Work out other sizes with the box blank calculator.

Estimated compression strength

Simplified McKee estimate for the empty box at 18 × 8 × 8 in. The flap style barely changes McKee's answer, because it depends on the walls; extra flap layers help with drops and side stacking more than with top-to-bottom load.

ECT, lb/inB flute BCT, lbfC flute BCT, lbf
32 ECT479535
44 ECT658736
48 ECT718803

Estimate only. Confirm with an ASTM D642 test before relying on it. Run the McKee calculator.

When to use it

Good for

  • Dense, heavy contents in long boxes
  • Ends that take impacts, such as long parts handled by one end

Watch for

  • The most board-hungry of the slotted family
  • Long outer flaps on wide boxes are hard to close by hand

Open the Spec Builder to check style, grade and dimensional weight for your product.

Related styles

Sources

  1. Fibre Box Association, "Box Styles Basics" (2014), hosted by IoPP
  2. FEFCO: The FEFCO Code (International Fibreboard Case Code), 12th edition
  3. McKee, R.C., Gander, J.W. & Wachuta, J.R. (1963). "Compression strength formula for corrugated boxes." Paperboard Packaging 48(8): 149–159

Last reviewed . See all sources and how Packgent computes.