275-300mm Three-Point Internal Measuring Device With Carbide Measuring Faces, 140mm Depth, Ratchet, Supplied In Case - Metav IndustryLine

Take advantage of a robust combination of repeatable measuring force, wear‑resistant carbide contact faces and workshop‑grade accuracy to keep inspection routines efficient; order via Metav Werkzeuge or consult our specialists for application advice.

Three‑point internal micrometer M312.153 — 275–300 mm, carbide measuring faces

M312.153 is a precision analogue three‑point internal micrometer designed for reliable internal diameter checks in machining and inspection environments with a 275–300 mm range

• Large 275–300 mm measuring range
• Carbide measuring faces for wear resistance
• Ratchet stop ensures repeatable measuring pressure
• Supplied in transport case without setting ring

Highly repeatable measurements for medium‑sized bores

The three‑point design with self‑centring contact geometry converts small adjustments into a stable diameter reading, making this instrument ideal for repetitive checks on medium‑sized bores. The 275–300 mm range covers common components in assembly and maintenance work while the ratchet stop enforces a consistent measuring force, reducing operator‑induced scatter. With an analogue vernier that provides a resolution of 0.005 mm and a specified accuracy of ±0.009 mm, the tool balances sensitivity and robustness for standard workshop quality assurance.

Durable contact faces and corrosion‑resistant scale for long service life

Wear is a major contributor to drift in measuring tools. The measuring faces are manufactured from carbide, delivering high abrasion resistance and stable contact geometry over prolonged use. The matt chrome‑plated scale and vernier minimise glare for clear readings and help resist surface corrosion in workshop atmospheres. These construction choices reduce downtime for replacement and preserve measurement integrity across many inspection cycles.

Practical handling and alignment to workshop workflows

A measuring depth of 140 mm allows access to deeper bores without sacrificing stability. The analogue vernier format keeps the instrument simple to use and serviceable without batteries, while the ratchet stop prevents over‑tightening and helps achieve consistent contact. The tool is supplied in a transport case, which protects the micrometer during storage and transit; note that delivery is without a setting ring, so zero setting must be performed with in‑house references or supplied gauge blocks.

Suitable classification and typical applications

This instrument falls into the standard class for calipers and micrometers, covering the everyday needs of machine shops, toolrooms and maintenance departments that require a good compromise between reach and stiffness. Typical uses include verification of internal diameters on housings, sleeves and medium‑sized cast or turned parts, as well as spot checks during assembly operations where reproducibility is essential.

For precise internal measurement backed by Metav IndustryLine quality, contact Metav Werkzeuge for tailored purchasing advice and prompt dispatch from Emmerich

Technical data

• Article number: M312.153
• GTIN: 4054469119595
• Customs tariff number: 90173000
• eCl@ss: 21170335
• ETIM: EC003590

Core data

• Measuring range: 275–300 mm
• Measuring depth: 140 mm
• Resolution (vernier): 0.005 mm
• Accuracy: ±0.009 mm

Design & special features

• Analogue vernier, matt chrome‑plated scale and vernier
• Carbide measuring faces (HM)
• Ratchet stop for consistent measuring force
• Supplied in transport case; delivery without setting ring
• Category: three‑point internal micrometer

FAQ

How does the three‑point principle improve internal measurements?
The three‑point geometry of M312.153 centres itself inside the bore and reduces sensitivity to slight misalignment, so practical centring and stable diameter readings are achieved more quickly than with two‑point methods.

Is the instrument suitable for production spot checks?
Yes, the combination of a 275–300 mm range, ratchet stop and resolution of 0.005 mm makes M312.153 appropriate for routine production checks where repeatability and speed matter.

What maintenance keeps the measuring faces accurate?
Regular cleaning and light lubrication of the spindle threads, together with periodic inspection of the carbide measuring faces, will maintain the measuring geometry and prolong service life of the M312.153 micrometer.

Can the micrometer be used for different materials such as cast iron or aluminium?
The measuring faces are suitable for a wide range of materials; material‑specific handling (cleaning of chips, light oil film) is recommended when measuring abrasive or sticky surfaces to avoid contamination of the contact faces.

Is a setting ring included for calibration at delivery?
Delivery of M312.153 is without a setting ring; calibration or zero setting should be performed using in‑house reference standards or gauge blocks as required.

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