Open-ended tube with mitred end flanges Box Template Generator

Open-ended tube with mitred end flanges. A rectangular tube open at both ends, closed along the underside by two half panels that overlap instead of a glue lap. At each end a shallow flange folds inward — a band under the top and a strip half way down each side, mitred together at the two corners — which stiffens the mouth of the tube.

Checked against the plate. This blank has been compared side by side with the drawing in the FEFCO Code, 12th Edition, and matches. That is a statement about the drawing, not a guarantee — always cut and fold a sample before committing to a die.

What is Open-ended tube with mitred end flanges?

Open-ended tube with mitred end flanges is a carton insert or fitment. A rectangular tube open at both ends, closed along the underside by two half panels that overlap instead of a glue lap. At each end a shallow flange folds inward — a band under the top and a strip half way down each side, mitred together at the two corners — which stiffens the mouth of the tube.

Uses

High-volume packing lines, since a pre-glued blank erects in one movement

Advantages

Cut from a single blank, so there is one tool and one part to stock
Arrives glued and flat, and erects quickly by hand or by machine

Disadvantages

The glued joint sets the minimum order — short runs are rarely economical

Typical industries

General packing and light manufacturing

Recommended board grades

Folding boxboard or solid bleached board, typically 250–450 microns. Heavier board for larger cartons, lighter where the carton is filled by machine.

At a glance

Code	`F50.21`
Family	Folding carton (ECMA)
Also known as	F50.21.00.00, flanged open-ended tube
Blank size at this size	335 × 176 mm
Panels	15
Creases	18

Measured against the p.76 plate with scripts/plate-diff.py: score 0.992, MATCH, cut 0.992 found / 1.000 extra, crease 1.000 / 1.000. Panel run 17.23, 34.48, 27.08, 34.48, 17.23 against the plate's own B = 27.08 and H = 34.48, over a body 59.09 tall; flange 4.93 deep from x 34.47 to 96.03 with a 4.93 by 4.93 mitre crease in each ear. WHAT THE PLATE DOES NOT SAY: the two bottom halves measure 17.23, which is both H/2 and half of B plus the 7.38 overlap that closes the tube — this drawing cannot tell those two intentions apart, and H/2 is what is built.

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Open F50.21 in the generator

Other codes in this group

Browse every code, or read what the groups mean.

Every FEFCO code we build — all 244 of them, grouped.
FEFCO codes explained — what the four digits mean and what each group covers.
How to measure a box — inside, outside and crease-to-crease.
Flutes and calipers — why board thickness changes the blank.