Custom Case News
Stacking Strength of Injection-Molded Cases: What You Need to Know
When it comes to transporting mission-critical gear, protection isn’t the only factor to consider. Stackability plays a major role in how cases perform in the field, in storage, and during transit. For engineers, procurement teams, and program managers managing sensitive equipment, understanding how injection-molded cases behave under load is essential.
At Custom Case Pros, we specialize in providing reusable packaging solutions that are not only rugged and reliable but also intelligently designed to meet the logistical demands of your operations. One frequent question we receive: “How much weight can I stack on an injection-molded case?”
The answer, as with many technical questions, is: It depends.
Why We Don’t Publish a Hard Stack Weight Rating
Stacking limits for injection-molded (IM) cases are difficult to quantify with a single number due to the many variables at play:
- Load Placement: Is the weight evenly distributed or concentrated in one area?
- Contact Surface: Is the upper case aligned with ribbed support points or resting on a curved section?
- Handling and Environment: Will the cases be stationary in storage or bouncing around on the back of a truck in extreme heat?
Even subtle differences in how a case is loaded or stored can dramatically affect the stress points on its body, lid, and latches. That’s why we work closely with each client to understand your equipment’s size, weight, and use environment before recommending the right case and advising on stackability.
The Engineering Behind Stackable Strength
Although we avoid blanket weight ratings, injection-molded Pelican cases offer robust features that support confident stacking under most operational conditions. Here’s why:
- Ribbed Structural Design
Pelican’s signature external rib pattern isn’t just for looks, it enhances the case’s rigidity and reinforces the structure at critical load-bearing points. These ribs disperse pressure when cases are stacked, reducing stress on any one area and minimizing deformation.
- High-Performance Resin
Pelican’s proprietary polymer blend provides a high strength-to-weight ratio. It’s tough enough to withstand compression without adding excessive weight to your overall loadout. This resin also resists cracking and warping under temperature fluctuations, key in hot or cold environments where stack integrity might otherwise fail.
- Interlocking Lid & Base Geometry
Many Pelican cases, like the iM series, are designed with groove-and-ridge profiles. These mating surfaces help prevent lateral movement when stacked, locking cases together securely and promoting even weight distribution across the lid.
- MIL-STD & ATA Compliance
Cases like the Pelican iM2700 and iM2975 are tested to meet or exceed military (MIL-STD-810) and airline transport (ATA 300) standards. These specifications include performance evaluations for drop, vibration, and stacking survivability, giving you peace of mind in high-stakes environments.
When Stackability Matters Most
Injection-molded cases are a great solution when:
- Space is limited and vertical stacking is the only option.
- Cases will remain stationary for long periods, such as in warehousing or onboard ship storage.
- Your operation includes frequent unloading and re-stacking, where groove-and-ridge interlocks reduce the risk of shift or collapse.
For field applications that involve heavier loads or extreme abuse, rotationally molded cases might be the better option. These offer thicker wall sections and deeper structural ribs designed for extreme stacking and transport conditions.
Custom Guidance is Key
While injection-molded Pelican cases provide excellent stack strength for most applications, we strongly recommend a design consultation for any project involving heavy or sensitive gear. The right recommendation isn’t just about case dimension, it’s about understanding:
- The weight and dimensions of your parts
- The environment your case will be used in
- Whether the case will be stacked, palletized, or lifted frequently
- The access and layout needed inside the case (including custom foam)
At Custom Case Pros, we use our in-house engineering expertise to assess these variables and match you with the right case and foam design for your operational demands.
Final Thoughts
Injection-molded cases offer an ideal combination of strength, weight savings, and stackability when used correctly. While we can’t assign a one-size-fits-all stacking limit, the built-in structural reinforcements and high-performance materials make them an excellent choice for most applications.
Need help selecting a case for your next project? Whether you’re transporting avionics, medical instruments, or military-grade tools, we’ll help you find the right solution and stack the odds in your favor.
Contact us at (405) 566-9290 or info@customcasepros.com, or submit your project details here. Let’s engineer a case that works as hard as you do.