ECT vs Burst Strength: Reading the Two Numbers on a Box Spec

Published: 2026-08-29 | Category: Engineering | Author: Yoco Group Editorial

Edge crush test (ECT) measures the box's compression resistance — how well it stacks — while burst (Mullen) measures the board's resistance to puncturing force. Modern logistics weights ECT, but both numbers tell part of the story.

The Scenario: The spec that confused a buyer

A buyer compared two "same strength" boxes — one spec'd 32 ECT, the other 200 lb burst. They performed differently in stacking, and the buyer learned the two numbers measure different properties.

Pain Points

ECT and burst are conflated by buyers;
Stacking failures happen to high-burst, low-ECT boxes;
Specs are compared without knowing what each number proves.

The Solution: The two numbers decoded

ECT and burst measure different failure modes:

1. ECT (edge crush) Compresses a board edge to measure stacking strength — the number that predicts pallet performance.

2. Burst (Mullen) Pressures a board face until it ruptures — a puncture-resistance measure for rough handling.

3. Which matters? For stacked distribution, ECT matters most; for puncture-prone handling, burst informs board choice.

The Result: Spec the number that matches the journey

The buyer re-spec'd to ECT for their stacked, palletized route and kept burst as a secondary check. Reading the two numbers is the difference between a spec and a story.