300xØ29 Extension for Three-Point Internal Micrometer Compatible with Series M312.146/M312.157/M312.256/M312.267 - Metav IndustryLine

Extend measuring reach and preserve alignment with the M312.155 extension: its 300 mm length and Ø29 mm profile convert three-point internal micrometers into reliable large-range gauges, while direct compatibility with the M312.146–M312.157 and M312.256–M312.267 series cuts integration time. Order the extension via Metav Werkzeuge or ask the team for application guidance.

M312.155 Extensions — 300 mm × Ø29 mm for three-point internal micrometers (Metav IndustryLine)

The M312.155 is an extension engineered to increase the measuring range of three-point internal micrometers for large-bore internal measurements in workshops and metrology environments.

• 300 mm extension Ø29 mm
• Compatible with series M312.146–M312.157
• Accessory for three-point internal micrometers

Reach larger bores without compromising stability

Adding a dedicated extension increases the effective measuring range while keeping the sensing geometry intact. The 300 mm length and Ø29 mm shank are specified to maintain axial alignment with the micrometer head, which reduces probe tilt and measurement scatter on large diameters. For production and quality-control tasks, this means fewer setups and faster throughput, because larger components can be measured without constructing temporary fixtures. The design supports reproducible contact and stable centring over the extended span.

Fast fit and reliable compatibility with existing systems

Compatibility with the M312.146–M312.157 and M312.256–M312.267 series ensures straightforward integration into existing three-point internal micrometer setups. The extension is intended as a direct mechanical add-on, avoiding adaptations that can introduce runout. This reduces downtime during retrofits and simplifies tooling logistics: the same micrometer head can be used across a wider range of components. The clear series matching cuts procurement complexity and helps maintain a consistent measurement chain.

Practical benefits for workshop and laboratory use

Using a purpose-made extension minimises handling and measurement uncertainty compared with improvised solutions. For calibration routines and repeat inspections, a dedicated extension provides defined geometry that supports traceability and consistent repeatability. The unit’s compact mass assists in handling while preserving stability, making it suitable for bench-mounted metrology and light workshop use. Where repeatable bore measurements are required, the extension helps preserve the original instrument’s performance over an extended range.

For precise large-bore measurements, request the M312.155 extension from Metav Werkzeuge in Emmerich; Metav’s specialists can confirm compatibility and delivery options by phone or e‑mail.

Technical data

• SKU: M312.155
• GTIN: 4054469119618
• Manufacturer: Metav IndustryLine
• eClass: 21019104
• ETIM: EC002219

Key dimensions

• Extension: 300 × Ø29 mm
• Weight: 1 kg
• Tariff number: 90173000

Compatibility / Special features

• Compatible with series M312.146–M312.157 and M312.256–M312.267
• Accessory for three-point internal micrometers
• Category: Accessories (Zubehör)

FAQ

What is the total extension length and shank diameter?
The extension measures 300 × Ø29 mm as delivered with the M312.155 and is specified to extend the reach of three-point internal micrometers.

Which micrometer series does this extension fit?
This accessory is compatible with the M312.146–M312.157 and M312.256–M312.267 series and is intended for use with three-point internal micrometers.

Is the extension supplied ready to use on the micrometer?
The product is a mechanical extension for the three-point internal micrometer system; mounting is performed according to the micrometer series’ interface and does not require additional adapters when matched to the listed series.

What is the weight of the extension?
The M312.155 has a mass of 1 kg, which supports stable handling while limiting added inertia during measurement.

Does the product data state the material or coating used?
The provided product data does not specify material or coating for this extension.

Manufacturer / Responsible: Metav Werkzeuge GmbH; Parkring 45; 46446 Emmerich; Germany; +49 2822 7131930; info@metav-werkzeuge.com