20–25mm Three-Point Internal Micrometer With Carbide Measuring Faces, Setting Ring, Packed Case - Metav IndustryLine

Take advantage of a compact measuring instrument that combines three-point contact stability, carbide measuring faces and mechanical accuracy of ±0.005 mm to improve repeatability in small-bore inspection. Order the item directly via Metav Werkzeuge or consult our specialists for application advice.

M312.135 — Three-point internal measuring micrometer, 20–25 mm range, carbide faces (Metav IndustryLine)

The M312.135 is a precision three-point internal measuring micrometer for reliable measurement of small bores and blind holes in workshops and inspection benches

• Three-point contact for stable internal measurement
• Carbide measuring faces for long wear resistance
• Accuracy ±0.005 mm for fine mechanical control

Consistent internal measurement where it matters most

This three-point internal measuring micrometer delivers stable contact by engaging three symmetrically arranged anvils, which reduces tilting and improves centring in cylindrical bores. The instrument’s three-point contact principle converts small angular misalignments into repeatable radial readings, making it particularly suitable for internal diameters between 20 and 25 mm. For workshop environments that demand reliable checks rather than optical inspection, this mechanical solution offers a compact alternative with straightforward handling and predictable results.

Durable contact surfaces and a serviceable scale

The measuring faces are made of carbide, which increases resistance to abrasion and preserves measurement geometry over repeated cycles. The scale and vernier are matt chrome-plated, reducing glare and providing a robust reading surface for analogue use. With a certified mechanical resolution and a verified accuracy of ±0.005 mm, the instrument maintains performance for routine quality-control rounds and set-up tasks. Regular light maintenance—cleaning and lubrication of the spindle and anvils—keeps the device within its specified tolerance window.

Compact classification and typical applications

Classified as a Micro instrument (measuring range up to 100 mm), this micrometer is optimised for fine mechanical work such as small-bore components, watch and micro-assembly, and test fixtures. It is designed for internal measurements including blind bores, where the three-point system and the adjusting ring ensure secure contact even when access is limited. The tool is compliant with DIN 863, aligning it with familiar workshop standards and enabling straightforward integration into existing inspection routines.

Speak with Metav Werkzeuge for tailored application advice and secure the M312.135 for precise internal measurements from our Emmerich quality hub

Technical Data

• Article number: M312.135
• GTIN: 4054469119489
• EClass: 21170335
• ETIM: EC003590
• Category: Measuring micrometers (three-point internal)

Core data

• Measuring range: 20–25 mm
• Minimum measuring range: 20 mm
• Maximum measuring range: 25 mm
• Accuracy: 0.005 mm
• Readout: analogue vernier
• Length: 90 mm
• Adjusting ring: 25
• Standard: DIN 863

Materials and features

• Scale and vernier matt chrome-plated
• Carbide measuring faces
• Suitable for blind-hole (sack) measurements
• Four-digit numeric identifiers and category mapping included

FAQ

How does the three-point contact improve measurement reliability?
The three-point contact design ensures the anvils centre within the bore and minimise tilt; the M312.135 uses this geometry to produce repeatable radial readings for small internal diameters.

Can this micrometer measure blind bores?
Yes, the instrument is suitable for blind-hole measurement and includes an adjusting ring to adapt the contact geometry for such applications.

What accuracy can be expected during routine checks?
The internal measuring micrometer provides an accuracy of ±0.005 mm when used under normal workshop conditions and maintained as recommended.

Is the scale corrosion-resistant and easy to read?
The matt chrome-plated scale and vernier reduce reflection and offer a durable reading surface suited to analogue inspection workflows.

Which standard does the device comply with?
The instrument is manufactured to meet DIN 863, aligning it with common mechanical measuring norms.

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