4.1 Load Carrying Capacity: 

4.1.1 Most architectural specifications contain a uniform load requirement based on Specification C635. Additionally, it is useful to know the uniform loads of cross runners to evaluate their suitability for various ceiling loads.

4.1.2 The procedure detailed in this standard is intended to be used for the simple 4 ft span specified in Specification C635 but it can be used for simple spans other than 4 ft.

4.1.3 Various concentrated load combinations can be similarly tested or they can be calculated from the uniform load results by engineering analysis.

4.2 Connection Strength in Tension and Compression: 

4.2.1 Structural failure of grid systems under axial loading is controlled by the failure of connections between the grid members. Specification of the allowable axial loads is useful for designers and specifiers for determining which grid systems will be appropriate for specific job conditions.

4.2.2 Connection strength is particularly important where the grid installation is expected to experience lateral loads due to earthquake or wind.

4.2.3 Connection strength in both compression and in tension are specified in Practice E580 as mean ultimate test load in tension and in compression.

1.1 These test methods cover metal ceiling suspension systems used primarily to support acoustical tile, acoustical lay-in panels, or suspended T-bar type ceiling systems.

1.2 These test methods cover the determination of strength properties of suspended ceiling grid system components as follows:

Tests

Subsections

Load Carrying Capacity

5.1

Connection Strength in Tension

5.2.2; 5.2.4

Connection Strength in Compression

5.2.3; 5.2.5

Wire Pullout Resistance

5.3

1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.

1.4 The following safety hazards caveat pertains only to the test methods described in this specification. 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.