FEFCO 0202: Overlap slotted container (OSC)

An overlap slotted container is an RSC whose flaps are cut longer than half the width, so the outer flaps overlap in the middle instead of just meeting. The overlap gives a stitching or gluing strip and a little more board over the center.

Dieline

Drawn by Packgent from the style's flap rule. Solid lines are cuts, dashed lines are scores.

Construction

Same four-panel body and manufacturer's joint as an RSC.
All flaps share one length, longer than W ÷ 2 by the chosen overlap. Packgent's drawing uses a 1 in overlap; your box maker may use more.
The overlap is limited by the width: once it reaches the full width the box becomes a full overlap (0203).

Flap and panel rule
Part	Size
All flaps	(W ÷ 2) + overlap ÷ 2
Overlap at center	set by the buyer, less than W

Closure. Staple or glue through the overlapping strip, or tape over it. The overlap is what makes stapling practical.

Blank size

Blank width is H + W + overlap. Everything else matches the RSC.

Worked example at 14 × 10 × 8 in inside
Board	Nominal blank, in	With allowances, in	Area, ft²
B flute	49.25 × 19	49.75 × 19.25	6.65
C flute	49.25 × 19	49.88 × 19.31	6.69
BC double wall	49.25 × 19	50.38 × 19.56	6.84

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 14 × 10 × 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/in	B flute BCT, lbf	C flute BCT, lbf
32 ECT	460	514
44 ECT	633	707
48 ECT	690	772

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

When to use it

Good for

Closures that are stapled or glued through two layers
Boxes that need a little more board across the center than an RSC

Watch for

Longer flaps make the blank wider, so it uses more board per box
The overlap must be specified; there is no single standard figure

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

Related styles

Sources

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

Last reviewed 2026-10-27. See all sources and how Packgent computes.