The TAPPI T 556 standard specifies a method for measuring the flexural strength of paper and Cardboard by single-point bending. This method evaluates the flexural performance of paper and Cardboard by placing the specimen in a Bending tester, applying a single-point bending force, and measuring the maximum resistance of the specimen when it breaks or reaches a specified deformation. Flexural strength is an important indicator of the ability of paper and Cardboard to resist bending deformation during use, and is widely used in fields such as Encasement, printing and writing paper. This standard provides the paper industry with a standardized test method to help optimize product mass and ensure the durability and Reliability of paper and Cardboard in practical applications.