Single Wall Box

The Edge Crush Test (ECT) is a laboratory test method used to measure the cross direction crushing of a sample of corrugated board. It provides information on the ability  of a particular board construction to resist crushing. ECT is a measure of the edgewise  compressive strength of corrugated board. It is measured by compressing a small segment of board on edge between two rigid platens or plates perpendicular to the direction of the  flutes until a peak load is established. 

The Bursting (Mullen) Test is another test used throughout the corrugated industry to  determine strength. It is related to the rough handling durability of corrugated  material. Bursting strength is reported in pounds (for example, 275#). 

It is important to understand what type of corrugated you are using before deciding to  substitute any equivalent. For example, if you are shipping a product that weighs between  25-40 pounds, a 32 ECT single-wall carton should be sufficient, in most cases. If your  carton is going to be subjected to severe handling, the 200# carton might be a better  option. It would be equivalent to a carton with an ECT of 32 or higher, and the bursting  test is more of a true measure of rough handling.