Self-Locking Tray with Locking Ears — Model 3

Reading the code FEFCO 0427

The 04 series holds the folder-type boxes and trays: usually one-piece, unglued constructions erected by folding the die-cut blank around or under the product. This is the series of trays, folders and mailers that hold their shape by geometry — locking tabs, ears and hinged lids instead of a glued joint.

Within the series, 0427 is the design published as the Tray with Self Locking Wall and Locking Ears. The four-digit code carries the full structural intent — specify it to any converter and both sides mean the same construction; only dimensions and board grade remain to be agreed.

This template is catalogue variant 2 of the 0427 construction, with adjusted proportions or construction detail; the FEFCO code identifies the underlying design.

How the structure behaves

The walls fold up and lock via ears that seat into cut slots, pinning the construction square — the tray erects by hand in seconds with no glue or tape, and the same lock geometry resists the walls being pushed back open.

Typical uses

This lock-and-ear construction is the backbone of today's e-commerce mailer boxes: shipped flat, erected at the packing bench, presentable enough to be the retail-facing box.

Dimensions and board

The parameters above — internal length, width and depth, plus any construction-specific values this style needs — drive the whole blank: panel layout, flap depths and slot positions all derive from them, validated against the template's supported range. The 2D dieline and the 3D fold preview regenerate together from the same parametric structure.

A corrugated dieline is a starting point for production, not a substitute for converter judgment: flute profile, board grade and joint style all affect final dimensions and crush behavior. Confirm tolerances and material with your manufacturer before mass production — and erect the structure on screen first, so flap collisions and proportion problems surface before any tooling is ordered.

What is Self-Locking Tray with Locking Ears — Model 3?

FEFCO 0427 is the corrugated design published in the FEFCO International Fibreboard Case Code as the Tray with Self Locking Wall and Locking Ears; the four-digit code specifies the full construction, leaving only dimensions and board grade to agree. This template is catalogue variant 2 of the construction.

Which dimensions does the Self-Locking Tray with Locking Ears — Model 3 dieline need?

4 parameters drive the blank: L (length), W (width), D (depth), Corrugated cardboard thickness (mm). Each value is validated against the template's supported range, and the whole dieline regenerates from them.

Can I see how Self-Locking Tray with Locking Ears — Model 3 folds before cutting it?

Yes. The interactive 3D fold preview and the 2D dieline are generated from the same parametric structure, so the fold you watch on screen is the geometry of the sheet you cut. Open the template in the preview studio to fold it at your own dimensions.