SB4 is a 4-Step Test Block fabricated from 1018 Steel (without Certification) for convenient confirmation of thickness gauge calibration, when NIST-Traceable Calibration Step Blocks are NOT REQUIRED. Supplied in a plastic case.
SB6 is a 6-Step Test Block fabricated from 1018 Steel (without Certification) for convenient confirmation of thickness gauge calibration, when NIST-Traceable Calibration Step Blocks are NOT REQUIRED. Supplied in a in felt-lined wood box.