Starrett 52998 Interchangeable Anvil Micrometer 36-42 in

Product Description

The STARRETT 52998 is a mechanical interchangeable anvil micrometer designed for large-diameter precision measurement in the 36 to 42 inch range. It features a friction thimble for consistent measuring pressure and a ring-type lock nut to secure the spindle at the desired reading. Graduation is 0.001 inches, giving technicians and machinists the resolution needed for close-tolerance work on large bores, shafts, and structural components. The spindle and anvil are both steel construction. This tool is intended for use by machinists, metrologists, and precision measurement professionals working with oversized workpieces.

The STARRETT 52998 is suited for shop-floor and inspection-room applications where large external dimensions must be verified with mechanical precision. The interchangeable anvil system allows the single micrometer body to cover the full 36 to 42 inch span by swapping anvils, reducing the need for multiple dedicated instruments. The package includes 37, 39, and 41 inch standards, a lock nut, and a wrench, providing the accessories needed for calibration and setup at each anvil position.

Key Features

• Mechanical operation — no battery or electronics required
• Friction thimble ensures repeatable measuring force
• 0.001 inch graduation for close-tolerance large-diameter measurement
• Ring-type lock nut secures spindle position during reading transfer
• Interchangeable anvil design covers 36 to 42 inch range with 2 anvils
• Includes 37, 39, and 41 inch standards, lock nut, and wrench for full setup

Compatibility

Designed as an OEM-style replacement or direct-use interchangeable anvil micrometer for large-diameter mechanical measurement applications in the 36 to 42 inch range.

Installation Notes

This instrument is used by machinists and metrologists and does not require installation in the traditional sense, but proper setup is essential for accurate readings. Before use, verify the micrometer with the included standards at each anvil position and zero as needed. Handle the anvils and spindle contact surfaces carefully to avoid nicks or contamination that would affect measurement accuracy. Follow the manufacturer instructions for wrench torque when securing anvils to the micrometer body.