Need Boxes Engineered for Stacking Performance?
President Container Group designs corrugated packaging with the right ECT rating for your supply chain. Our structural engineers ensure your boxes perform under real-world warehouse conditions.
What Is the Edge Crush Test (ECT)?
The Edge Crush Test, commonly abbreviated as ECT, is one of the most widely used methods for evaluating the strength of corrugated board. It measures the force, expressed in pounds per linear inch, required to crush a small sample of corrugated board standing on its edge. This measurement directly correlates with a finished box’s ability to resist compressive forces when stacked on a pallet in a warehouse or during transit.
ECT has largely replaced the older Mullen Burst Test as the preferred strength metric for many applications because it more accurately predicts real-world stacking performance. You will often see the ECT value printed on the Box Manufacturer’s Certificate (BMC) stamp found on the bottom flap of most corrugated boxes.
How ECT Ratings Work
ECT values typically range from 23 ECT for lightweight single-wall board up to 71 ECT or higher for heavy-duty double-wall and triple-wall constructions. The higher the ECT number, the greater the board’s resistance to edge-on compressive force. Common ECT grades include 32 ECT (a standard single-wall board suitable for many general applications), 44 ECT (a stronger single-wall option for heavier products), and 48 ECT or above for demanding industrial loads.
When specifying packaging, selecting the correct ECT value requires understanding how many boxes will be stacked, how long they will be stored, and what environmental conditions they will face. Humidity, for example, can significantly reduce corrugated board strength over time.
ECT vs. Mullen Burst Test
While ECT measures resistance to crushing forces (stacking), the Mullen Burst Test measures resistance to puncture. Both metrics serve important but different purposes. ECT is the better indicator if your primary concern is pallet stacking in warehouse environments. Mullen is more relevant when contents might push outward against box walls or when puncture resistance is critical during rough handling.
Many buyers specify ECT-rated board because it can achieve equivalent stacking strength with less material, potentially reducing costs and environmental impact. At President Container, our engineering team helps you choose the right standard for your specific product and distribution requirements.
Why ECT Matters for Your Packaging
Selecting the proper ECT rating protects your products, reduces damage claims, and optimizes material costs. Over-specifying wastes money on unnecessary board weight. Under-specifying risks crushed products and expensive returns. The Box Compression Test (BCT) evaluates the finished box rather than just the board, giving you a complete picture of performance when combined with ECT data.
President Container Group’s structural design team uses ECT values alongside advanced CAD design tools to engineer packaging that meets your exact performance requirements while minimizing material usage. Our sustainability commitments, including FSC and SFI certifications, mean you get strong boxes built with responsibly sourced materials.
Frequently Asked Questions
What ECT rating do I need for my boxes?
The required ECT depends on your product weight, stacking height, and storage duration. A 32 ECT single-wall box works well for many consumer goods under 65 pounds, while heavier or taller stacks may require 44 ECT or double-wall construction. Contact our engineering team for a recommendation based on your specific needs.
Is ECT or Mullen better for my application?
ECT is typically preferred when warehouse stacking is the primary concern. Mullen is better suited when puncture resistance matters most, such as with sharp or irregularly shaped contents. Many corrugated buyers have transitioned to ECT-rated board for cost and performance benefits.
Where can I find the ECT rating on my box?
The ECT value is printed on the certificate stamp located on one of the bottom flaps of the box. It will list either an ECT value or a Mullen burst test value, along with other board construction details.
Get Packaging Engineered to Perform
President Container Group · 200 W Commercial Ave, Moonachie, NJ 07074 · (201) 933-7500