This Supplement C to AWS Standard QC7, Standardfor AWS Certified Welder Program, describes testing administratedby Accredited Test Facilities to the requirements of AWS QC4-89, Standard for Accreditation of Test Facilities for AWSCertified Welder Program. The welder performance testing for this Supplement was developed using ANSI/A WS D9.1,Sheet Metal Welding Code, as reference.