SPI 75889253 is a double-end plug thread Go/No-Go gauge for 1 4-20 threads, classified to Class 2B tolerance. The double-ended design accommodates separate go and no-go checks on a single tool, enabling quick verification of thread acceptance to the specified tolerance. In quality control, it helps confirm that plug threads meet the Class 2B tolerance for 1 4-20 sizes without over- or under-sized conditions.
