Purpose:This specification covers the procedures for approval of products of premium-quality titanium-base alloys and the controls to be exercised in producing such products. Application: For Critical@ highly-stressed parts of titanium-base alloys which require approval of the product and facets of its production to assure that production lots of the product are of the same metallurgical quality and are produced by the same basic procedures as the products originally qualified; applicable to parts subjected to rigid inspection standards throughout manufacture from ingot to finished part. Classification: This specification covers two grades of premium-quality titanium-base products based on the melting practice used in making the alloy@ as follows: Grade 1 - Double Vacuum Melted Grade 2 - Triple Vacuum Melted Either grade may be furnished unless a specific grade is specified.