Threaded Plug Gauge Assembly Dimension Type Inch Gauge Type Go/No-Go (Plus/Minus) Handle Design Double End Included Handle Taperlock 1 Thread Class 2B Thread Size 5/16 In.-18 Thread Type UNC Tolerance Class X Gauge Finish Chrome Plated Gauge Length - Go Member 1/2 in Gauge Length - No-Go Member 5/16 in Gauge Material Tool Steel Handle Color Blue Handle Length 2 3/4 in Hardness RC 70-72 Included Certification Certificate of Accuracy with NIST Traceability