Mitutoyo 139-179 Inside Micrometer Extension Rod Set 4-36 In Range

The Mitutoyo 139-179 is a precision mechanical extension rod set designed for use with inside micrometers to measure internal diameters from 4 to 36 inches. This comprehensive set includes five extension rods in graduated lengths (1 inch, 2 inches, 4 inches, 8 inches, and 16 inches) that combine with micrometer heads and anvils to achieve accurate inside measurements across a wide range of applications.

Key Features:

• Measurement range: 4 to 36 inches with 0.001 inch graduation
• Five hardened steel extension rods: 1 in, 2 in, 4 in, 8 in, and 16 in lengths
• Compatible with Mitutoyo inside micrometer heads for versatile ID measurements
• Supplied in a fitted wooden storage case for organization and protection
• Precision ground contact points for accurate, repeatable measurements

This extension rod set is ideal for machinists, quality control inspectors, and tool and die makers who need to measure large bore diameters, cylinder bores, pipe IDs, and other internal dimensions with high precision. The modular design allows users to configure the exact length needed by combining different extension rods, making it a versatile solution for inspection and manufacturing applications.