This specification covers the required properties of only the ground surfaces of interchangeable taper-ground joints used in laboratory and industrial equipment in full-length, medium length, short length, and international length grindings. It includes information on the testing method for the products. After testing, samples should conform to the required quality of surface finish, taper, and leakage for the specific joint size designation.

1.1 This specification covers designations, dimensions, and tolerances for only the ground surfaces of interchangeable taper-ground joints for laboratory and industrial equipment in full-length, medium-length, short-length, and international-length (ISO K-6 series) grindings.

Note 1: The dimensions pertaining to full-length, medium-length, and short-length joints, other than for the tolerance on length of grind, were taken directly from the now obsolete Commercial Standard CS 21.

Note 2: Tolerances on the diameters of the international-length joints do not agree with those given in ISO Recommendation R 383. These tolerances have been established to agree with those of CS 21 in order to prevent the negative projection (large end of inner joint being smaller than large end of outer joint) permitted by ISO.

Note 3: Although glass is the most commonly used material for ground joints, other materials may be used as specified. Taper-ground joints constructed from glass should be of suitable chemical and thermal properties in accordance with Specification E438. Joints should be as free as possible of visible defects and conform to Specification E671.

1.2 The following precautionary caveat pertains only to the Test Method portion, Section 4, 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.3 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.