Product Guide

The Difference Between Auto-Bottom and Crash Lock Boxes Explained

Auto-bottom vs crash lock: how the mechanisms differ and which is right for your products.

3 min readUpdated April 2025

How each mechanism works

Both auto-bottom and crash lock boxes feature pre-glued bases that assemble without tape. The difference lies in the folding mechanism. They are often confused because both offer "automatic" base assembly, but the engineering is distinct.

Crash lock: the base panels interlock when pushed flat. Two pre-glued flaps fold inward and lock against each other.
Auto-bottom (auto-erect): all four base panels are pre-glued. When the box walls are opened, the base folds flat automatically by gravity.
Both eliminate tape on the base and assemble in seconds
The terms are sometimes used interchangeably but they are technically different mechanisms

Quick answer

Crash lock boxes require a push to lock the base; auto-bottom boxes fold flat automatically when opened. In practice, the difference is subtle. Auto-bottom is marginally faster (gravity does the work), while crash lock gives a more definitive "locked" feel. Both are significantly faster than manual fold-and-tape boxes. For most applications, either works well.

Side-by-side comparison

Both take 5-10 seconds. Auto-bottom may be 1-2 seconds faster due to gravity-assisted folding.

The interlocking mechanism gives a tactile "click" that confirms the base is locked.

The gravity-fold mechanism is easier for robotic packing systems to handle.

Both provide excellent base integrity. The difference in strength is negligible for most applications.

When to use each

Crash lock is best for: e-commerce, manual packing operations, and applications where a secure "locked" feel matters
Auto-bottom is best for: automated packing lines, very high volumes, and retail shelf-ready packaging
Either works for: most standard fulfilment, subscription boxes, and general product packaging
From ProcuraPack

Crash lock boxes from ProcuraPack

Reliable crash lock boxes with a firm locking base for e-commerce and fulfilment operations.

Browse crash lock boxes

Frequently asked questions

Crash lock requires a push to interlock the base; auto-bottom folds flat automatically when the walls are opened.

Both take 5-10 seconds. Auto-bottom may be marginally faster due to gravity-assisted folding.

Both provide excellent base strength. The difference is negligible for most applications.

They are often used interchangeably but technically refer to different base mechanisms.

Auto-bottom is slightly easier for robotic systems. Crash lock works better for manual packing operations.

Part of our guide

Product Guide: Crash Lock Boxes

Expert insights on crash lock packaging, from materials and design to branding and sustainability.

Browse all guides →