Tile are normally pressed in dies having true 90° angle construction. However, minor variations in die fill, compacting pressure, and heat treatment can result in finished tile with acute and obtuse angles. This out-of-squareness results in a difference in length of opposite sides, and the tile may have the appearance of a keystone or wedge.

Excessive wedging presents difficulties in the installation of tile. This test method provides a means for determining the degree of wedging.

1.1 This test method covers the determination of the wedging or deviation from rectangularity of flat, rectangular wall and floor tile. The test method covers tile as defined in Terminology C 242.

1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.