Meet the JBO Thread Ring Gauge (GO) for BSF—your go-to tool for verifying external thread diameters on right-hand BSF fasteners. Designed for machinists, inspectors, and production teams, it provides fast, reliable GO checks to confirm the 3/8 x 20 BSF size with medium-class tolerance is met. Built for daily use in busy workshops, this gauge combines precise dimensions with robust materials to deliver consistent results over time.

• Go/No-Go quick checks: Enables fast GO testing of external threads to verify diameter and pitch accuracy, speeding inspections and reducing rework in quality control.
• Durable hardened steel construction: Withstands wear and heavy use, maintaining measurement accuracy and extending service life in demanding shop environments.
• BSF Right-Hand 3/8 x 20, Medium Class accuracy: Precisely matched to the specified BSF right‑hand thread and tolerance, delivering reliable, repeatable results across parts and suppliers.

This gauge streamlines inspection workflows by providing a clear, tactile check for properly conforming threads. Its dedicated sizing and rugged build support consistent results, helping you meet tight production schedules, reduce downtime, and maintain high-quality standards across projects.