Interactive 3D

1 / 3

EVF21005

Solid-Base Flap Lock Box

Available in a wide range of custom configurations & material selection.
Order 1 sample. Or order 100K+ units. Or anything in between.
Affordable delivery across North America.
Design support, warehousing, testing, assembly available.
Widest machinery capability in America via 30+ specialist partner plants.

Get pricing

Free white-glove consultations. Blazing-fast response time. Fast quotes.

Product details

Top highlights

Solid bottom panel for premium presentation and secure weight bearing
Delivered flat for hand folding and interlocking
Double-wall front and back panels provide extra rigidity

About this product

The EVF21005 is a premium folding carton that uses interlocking side flaps and a roll-over front panel to create a completely solid base panel. Delivered flat without pre-glued seams, it relies on hand assembly to form the rigid box.

This box provides double-wall thickness on the front and back faces, making it a strong fit for retail presentation, kitting, and short-run fulfillment where a clean, unbroken bottom is more important than rapid packing speeds.

Common uses

Premium retail packaging
Low-volume kitting
E-commerce inner cartons

Get a quote

Share what you know. We'll take it from there. Or email us at info@herculeindustrial.com

Describe your project *

Approximate quantity *

Size if known

Files or competing quote (optional)Drag files here or choose filesAdd drawings, photos, dielines, quotes, specs, or other useful files.Max 5 files, 25 MB total.

Name *

Email *

Phone

Optional

More details

You can skip this whole part, or open a section and answer only what you know.

Size and quantity

Detailed dimensions

Units US customary (inches)Metric

What do your dimensions describe?

Length

Width

Depth

Size notes

Quantity notes

Materials and print

Paperboard preference

Add details for paperboard preference

Paperboard details

Print and artwork

Add details for print and artwork

Print, finish, or artwork details

Shipping or storage context

Custom changes or unusual needs

How will these boxes be packed?

What type of items will go inside?

How will the packed boxes be distributed?

Current box or specs

Do you have a current box, spec, or target sample?

Add details for do you have a current box, spec, or target sample?

Current box, known specs, or current problem

Destination ZIP or region

Company

Any deadline or timing constraint?

Retail Presentation and Kitting

Premium Retail Presentation

The unbroken bottom panel provides a clean, continuous surface that looks excellent on retail shelves. Without bottom flaps or glued seams, the package feels deliberate and high-quality.

Manual Kitting and Inner Cartons

For short-run fulfillment or multi-item kitting, this box provides a rigid, double-walled enclosure. It works well as a strong inner carton inside a master shipper, keeping the presentation intact when the customer opens the outer box.

High-End Component Packaging

When packing small electronics, cosmetics, or hardware, the solid floor prevents small parts from slipping through bottom gaps that might exist in a standard tuck-bottom carton.

Limited-Run Promotional Kits

Because this carton is delivered completely flat, it is often chosen for short promotional runs or trial programs where the labor of hand assembly makes more sense than committing to a pre-glued carton.

Premium Retail and Short-Run Fulfillment

Trial Programs and Limited Rollouts

An efficient choice for short-run digital programs or limited retail rollouts where hand assembly labor is acceptable and a premium, unbroken base is desired.

Heavy or Fragile Retail Items

The solid base absorbs product weight directly without the risk of bottom flaps giving way. The double-wall front and back add vertical compression support, protecting heavier items better than a standard single-wall tuck box.

Hand-Packed Assembly Lines

This carton is a practical fit for fulfillment centers that rely on hand packing, provided the team is trained on the specific sequence of folding the side walls, interlocking the inner flaps, and rolling over the front lock.

When to Consider Pre-Glued or Simpler Alternatives

Faster Packing Lines

The interlocking flaps and 180-degree roll-over panel require careful hand folding. If your packing line needs to move quickly, or if repeat order volume increases, evaluate a standard crash-lock or auto-bottom carton that opens with a quick push.

Standalone Parcel Shipping

This is a folding carton with a standard friction tuck lid. It is not designed to ship through a courier network on its own. If you are shipping directly to consumers, you will likely need an outer mailer or shipping box.

Board Caliper and Assembly Labor

Board Thickness and Locking Clearances

This box is highly sensitive to board caliper. The central slits on the inner flaps and the 180-degree roll-over front panel must be sized for your chosen material. If the board is too thick, the flaps may bow and the front lock might not seat correctly. A physical prototype on the exact production board is highly recommended.

Fulfillment Labor

Understand the assembly sequence before committing. The packer must fold the side walls up, interlock the inner flaps, fold the front wall up, and roll the top panel over to lock the box. This takes more time than loading a standard pre-glued box.

Print Panel Placement

The outer front, back, sides, and lid are fully available for graphics. Because the inner front and back walls are formed by flaps folding inward, they will display the inside surface of the sheet unless the board is printed on both sides.

Outer Shipping Requirements

Decide early whether this carton will be handed directly to a customer, placed on a retail shelf, or shipped in a parcel network. If it will be shipped, plan for a master carton or corrugated mailer to protect the unglued box.

Modifying the Flap Lock Box

Roll-Over Flap Height

The front roll-over panel can be adjusted. It should be long enough to stay securely tucked behind the front wall, but short enough to clear the product inside.

Window Patching

A window can be added to the lid or the outer front wall to display the product. Avoid placing windows on the side walls or the interlocking flaps, as this would weaken the assembled box.

Dust Flap and Tuck Lid Clearances

The friction fit of the top tuck lid and the supporting dust flaps can be adjusted based on the board grade to ensure the lid stays closed without binding during opening.

Packing details

Flat Delivery and Storage

Since the box is unglued, it ships completely flat. This maximizes pallet density and reduces storage space in your facility before the boxes are needed.

Additional notes

Board Caliper Sensitivity

The locking mechanism relies on precise friction. Changing the board grade after the initial design is approved will likely require the cutting die to be adjusted.

FAQs

Is this box suitable for fast packing lines?

The interlocking inner flaps and the roll-over front lock require specific hand manipulation. It is typically chosen for hand-assembly operations where presentation matters more than packing speed.

Is the bottom strong enough for heavy items?

The base is a single, solid panel. Because there are no bottom flaps or seams to give way, it handles downward weight very well, provided the overall board grade is appropriate for the product.

Can I use a thicker corrugated board for this box?

Moving to a thicker micro-flute requires careful adjustment. The interlocking slits and the 180-degree fold are calibrated for standard folding carton board. Thicker materials can cause the panels to bind or crack, making a physical sample an important step.

Will the inside of the box be blank?

By default, the inside of the box shows the unprinted side of the board. However, because the inner front and back walls are formed by flaps folding inward, those specific inner walls will also show the unprinted side unless you specify double-sided printing.

Does this box need tape to stay closed?

The main box locks together without tape or glue. The top lid uses a standard friction tuck. While it holds itself closed for retail display or kitting, it will likely require an outer shipper or heavy sealing if sent through a parcel network.

Why choose this over a pre-glued box?

It is delivered completely flat and provides a solid bottom and double-wall ends, offering a cleaner presentation than a standard glued tuck box.

How does the front roll-over panel work?

It folds over the interlocked side flaps to secure the front wall in place, relying on friction and board thickness rather than adhesive to hold the box together.

Why is board caliper so important for this box?

The interlocking slits on the side flaps and the friction fit of the front roll-over panel depend on the exact thickness of the paperboard. If the board changes, those cuts and scores usually need to be adjusted so the box folds cleanly.