Auto lock bottom box template
Enter the finished size of your carton and the dieline below redraws instantly: four body panels, a tapered glue flap, a tuck top on the front, and a crash-lock bottom with interlocking front and back flaps and 45° glue tabs on the side flaps. Open it in the Studio to design it, fold it in 3D and export the dieline as a 1:1 PDF, SVG or DXF.
Set your box size
- Flat sheet
- 377 mm × 503 mm
- Panels
- 15
Cutting template: a tuck top hinged on the front with slit-locked tuck, shouldered dust flaps and a thumb notch; at the bottom, front and back flaps that overlap past the middle and step at half their width to lock, and side flaps with a glue tab past a 45° crease. Width, depth and height are inside sizes; panels are creased one board thickness wider and the walls three boards taller for the layered bottom. Ask your printer to confirm the allowances and glue tabs for their board.
What is an auto lock bottom box?
An auto lock bottom box, also called a crash lock or auto bottom box, is a folding carton whose bottom is folded and glued at the factory. It ships flat, and when you open it the four bottom flaps swing down together and lock, so the carton is ready to fill in a second. The bottom is much stronger than a tuck, which makes it the usual choice for bottles, jars, candles, electronics and anything heavy.
What is on the dieline
The template draws every panel from your three measurements.
- Four body panels in one strip: side, front, side, back, with a glue flap with 15° tapered ends.
- A top lid on the front panel with a slit-locked tuck tongue, two shouldered dust flaps and a thumb notch in the back.
- Front and back bottom flaps that reach past the middle and step at half their width, so each lies over the other on one side and they lock.
- Side bottom flaps, each with a glue tab past a 45° crease at the corner where the flat carton folds.
- Adjustable glue flap, tuck, top dust flap and bottom side flap sizes in the Studio.
- Cut lines and crease lines kept separate, as in the PDF, SVG and DXF exports.
How the crash-lock bottom works
At the factory each glue tab is folded back along its 45° crease and glued to the inside of the front or back flap beside it, and the carton is folded flat with the bottom tucked inside. Opening the tube pulls those tabs, which swing the four flaps down into place, and the stepped front and back flaps lock over each other. Watch it fold in 3D in the Studio.
Auto lock bottom vs tuck end
A straight tuck end box or reverse tuck end box closes its bottom with a tuck, which costs less to make but holds less weight and has to be closed by hand. An auto lock bottom needs a glued bottom and costs a little more, but it sets up faster on the packing line and carries heavier products safely.
Is the auto lock bottom template free?+
Yes. The size picker and dieline here are free. Designing, saving and exporting happen in the Studio with a free account.
Is an auto lock bottom the same as a crash lock bottom?+
Yes. Auto lock bottom, crash lock bottom and auto bottom are names for the same pre-glued bottom that locks itself when the carton is opened. A snap lock (1-2-3) bottom is different: it is not glued and is folded closed by hand.
Are the sizes inside or outside dimensions?+
Inside. Each panel is creased one board thickness wider for the caliper you set, and the walls are three boards taller for the layered bottom, so the folded carton keeps the inside size you enter.
Can I download the dieline?+
Yes. The Studio exports a 1:1 PDF with your artwork, and the cutting template on its own as SVG or DXF with cut and crease lines on separate layers. Ask your printer to confirm the glue tabs and allowances for their board and gluer.