1.1 This specification covers vinyl-coated glass yarns. These yarns are manufactured in two basic classes. These classes have been established that when properly woven into screening, satisfactory strength, durability, and insect protection are obtained. The two classes are as follows:

1.1.1 Class 1—Nominal thickness 0.292 mm (0.0115 in.).

1.1.2 Class 2—Nominal thickness 0.330 mm (0.0130 in.).

1.2 The values stated in either SI or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with this specification.

1.3 The following precautionary statement pertains only to the test method portions, Sections 12-21, of 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 and health practices and determine the applicability of regulatory limitations prior to use.