Analog Inside Micrometer Set INSIZE 3-point 6–12 mm (model 3227-123)

The INSIZE Analog Inside Micrometer Set 3-point 6–12 mm is a precision measuring tool designed for accurate internal diameter measurement in workshops and inspection environments. The set includes a three-contact micrometer mechanism that centers automatically within a bore to provide stable and repeatable readings across the 6–12 mm range. Built for mechanical, metalworking and quality-control applications, the instrument offers a straightforward analog readout and robust construction suitable for routine measurement tasks.

Advantages

The three-contact design ensures consistent centring and minimizes measurement error from misalignment, while the analog scale provides immediate visual feedback without the need for batteries or electronics. The set format allows quick adaptation to different sizes within the specified range, reducing setup time for inspection and machining operations. Materials and finish resist typical workshop wear, supporting reliable repeatability and long-term use.

Suitable for

• Measuring internal diameters of small bores and holes in metal components
• Precision inspection and quality-control checks in workshops and production lines
• Setup and verification tasks in mechanical and metalworking operations

Key specifications

• Measuring range: 6–12 mm
• Contact type: three-point (three-contact) inside measuring head for automatic centring
• Display type: analog scale
• Construction: metal body with hardened measuring faces for wear resistance
• Measurement accuracy: precision micrometer-grade repeatability suitable for workshop inspection (see manufacturer documentation for exact tolerance values)

How to use

Select the appropriate setting from the set to match the approximate bore size, insert the three-contact head into the hole and rotate the thimble gently until the contacts seat against the internal surface. Take care to align the instrument roughly along the bore axis before final tightening to ensure the three contacts engage simultaneously and provide a centred reading. Read the measurement directly from the analog scale, recording the value. For best results, make multiple measurements at different depths and positions to confirm consistency.

Usage recommendations

Handle the micrometer with care to avoid shocks and contamination of the measuring faces. Clean the measuring surfaces and the bore to be measured before use, and store the set in its protective case when not in use. Calibrate or verify the instrument periodically against a reference gauge to maintain measurement reliability.