Industrial-grade 1-1/4-UNC 2B Thread Plug Gauge, a vintage machinist tool designed to verify internal threads. Specifically sized for holes tapped to 1-1/4 inches with UNC coarse thread and a 2B tolerance, this plug gauge provides a precise reference for inspection and quality control. Originating from a bygone era of precision machining, it serves as a compact, durable gauge for shop benches and inspection rooms. Use cases include checking machined components, jigs, and housings that require 1-1/4-UNC internal threads.
