Mitutoyo 64AAA212 Thread Measuring Wire 40 Tpi

Product Description

The MITUTOYO 64AAA212 is a thread pitch diameter measuring wire designed for precise thread measurement in metrology and quality-control applications. Each wire measures 1.125 inches in length with a nominal best wire diameter of 0.01443 inches and a nominal constant of 0.0173 inches. Engineered for 40 TPI threads with a 0.03-inch pitch, these wires are used with the three-wire method to calculate the pitch diameter of threaded parts to a high degree of accuracy. This set contains 3 pieces. It is installed and used by machinists, tool and die makers, and quality-control technicians who require repeatable, traceable measurement results.

These measuring wires are suited for use in precision manufacturing environments including job shops, aerospace, and general machining operations where thread pitch diameter verification is required. They are specifically designed for use with thread plug gages and micrometer-based measurement setups applying the three-wire contact method. The 40 TPI specification makes them appropriate for measuring fine-thread fasteners and threaded components produced to Unified National thread standards.

Key Features

• 40 TPI thread pitch compatibility with 0.03-inch pitch for fine-thread measurement
• Nominal best wire diameter of 0.01443 inches for accurate three-wire method results
• Nominal constant of 0.0173 inches simplifies pitch diameter calculation
• Wire length of 1.125 inches provides sufficient contact length for stable readings
• Set of 3 wires as required for the standard three-wire measurement method
• Designed for use with thread plug gages and precision micrometers

Compatibility

Designed for use with thread plug gages and micrometer setups employing the three-wire pitch diameter measurement method on 40 TPI threaded components.

Installation Notes

Thread measuring wires are used by machinists and quality-control technicians — no power tools or electrical shutoff is required. Ensure the micrometer anvils and wire surfaces are clean and free of burrs before use to avoid measurement error. Handle wires carefully to prevent bending or surface damage, as deformation will compromise measurement accuracy. Follow your facility or inspection standard for proper three-wire calculation procedures.