---
title: "lock box: Definition and Meaning | NPSA"
description: "A lock box is a steel housing that fits over a padlock on a container door. It encloses the lock to block bolt cutters and other tools."
url: https://npsa.preview.multisites.ai/glossary/lock-box
publisher: National Portable Storage Association (NPSA)
phone: "(816) 960-6552"
email: info@npsa.org
---

Container parts

# lock box

A lock box is a steel housing that fits over a padlock on a container door. It encloses the lock to block bolt cutters and other tools. Bolt-on and weld-on lock boxes are common add-ons for storage containers. It adds theft protection but is not a full security system.

## Why it matters

A lock box makes a container harder to break into. The padlock sits inside the steel housing, so a thief cannot easily cut the shackle. Operators often sell or install lock boxes with rentals. Customers choose them for job sites, rural storage and high-value tools. A common mistake is to buy a box that does not fit the container's door hardware. Many fit standard ISO hasps, but check before you order. A lock box adds protection but does not make a box theft-proof. Doors, hinges and locking bars still matter. Install it as the seller directs, and use a lock that suits the housing.

[Read: Shipping container sizes and dimensions for rental fleets](https://npsa.preview.multisites.ai/guides/container-sizes-and-dimensions)

Definition source: [siteboxstorage.com](https://siteboxstorage.com/store/shipping-container-bolt-on-lockbox/)

## Related terms

[### hasp A hasp is a hinged metal strap with a slot. It folds over a staple or loop and takes a padlock. On a container, the hasp on the door handle locks the locking bar in place. Standard ISO hasps are common.](https://npsa.preview.multisites.ai/glossary/hasp)[### door locking bar A door locking bar is a vertical steel rod on a container door. It turns in cam keepers at the top and bottom of the frame to lock the door tight and compress the gasket. Each door normally has one or two bars.](https://npsa.preview.multisites.ai/glossary/door-locking-bar)[### cargo door A cargo door is one of the two hinged steel doors at the end of a standard shipping container. The doors close on rubber gaskets and lock with vertical locking bars. They are the main way in and out of a container.](https://npsa.preview.multisites.ai/glossary/cargo-door)[### cam keeper A cam keeper is a steel bracket on the top and bottom of a container door frame. The cam on the locking bar sits in it. When the bar turns, the cam locks into the keeper and holds the door closed.](https://npsa.preview.multisites.ai/glossary/cam-keeper)[### container modification A container modification is a change made to a standard shipping container. It covers a single door cut-in up to a full fit-out. Common changes include doors, windows, vents, insulation, electrical work, HVAC, lining, partitions and plumbing. Sellers often group these changes into packages.](https://npsa.preview.multisites.ai/glossary/container-modification)[### portable storage container A portable storage container is a container made for rent or sale as movable storage. NPSA describes portable storage containers as ISO shipping containers retired from international shipping and offered on the domestic market. In practice the term also covers other portable units.](https://npsa.preview.multisites.ai/glossary/portable-storage-container)

[All 220 terms](https://npsa.preview.multisites.ai/glossary)

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