Features: Thread plug gauge is a tool used to measure the correctness of internal thread size. Thread plug gauge under 100mm features a taper shank design. Thread plug gauge 100mm and above features a double screw design. Easy to operate and maintain, with excellent performance. Specification: Material: Bearing steel Weight: 14~221g / 0.5~7.8oz Model: M1*0.25, M1.2*0.25, M1.6*0.35, M1.8*0.35, M2*0.4, M2.5*0.45, M3*0.5, M4*0.7, M5*0.8, M6*1.0, M8*1.25, M10*1.5, M12*1.75, M14*2.0, M16*2.0, M20*2.5 (Optional) Inspection and measurement process: 1. Clean the thread plug gauge and the measured thread before use. Use thumb and forefinger to rotate the ring gauge to ensure the thread engages freely over its full length; otherwise, accurate measurement cannot be achieved. 2. After verification by authorized inspection and metrology institutions, mate the screw plug gauge with the thread being measured. Rotate the ring gauge using thumb and index finger. The thread is considered合格 if engagement occurs within two pitch lengths; otherwise, the product is non-conforming. Package List: 1 x Thread Plug Gauge Note: 1. Before use, the thread plug gauge must be inspected and certified by relevant metrology authorities prior to deployment in production environments. 2. During use, ensure the thread tolerance class and deviation code of the measured thread match those marked on the thread plug gauge. 3. After use, clean the gauge and remove any attachments. Store in the designated container. Keep in a fixed, designated location at the production site. Handle with care to avoid impact and damage to the measuring surfaces. Do not force the plug gauge into a thread as a cutting tool, to prevent premature wear and maintain measurement accuracy. Note: The product may be delivered in either new or old version randomly. Please ensure you are comfortable with this before placing your order.