Magnetic V-Block

Inspection Equipment | UKAS Certified | Quality Control

Eley’s magnetic v-blocks are designed to hold rectangular, square, and cylindrical workpieces securely, so they can be inspected or machined accurately. 

 

With a holding power on the v-face of 90kgf and 110kgf on the surface, 3 magnetic surfaces are achieved simultaneously, helping keep round parts aligned, while the magnetic base adds stability during measurement or setup.

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  • Inspection and metrology tasks where shafts, rods and other cylindrical components need to be held in a stable, repeatable position for accurate measurement and verification.

  • Machining and grinding operations where reducing movement and maintaining concentric, straight alignment is essential for achieving consistent results.

  • Quality control applications involving the inspection of round components, helping to support repeatable checks on geometry and positioning.

  • Toolroom use for holding cylindrical parts securely during setup, adjustment and light machining tasks.

  • Workshop setup, especially for cylindrical parts, where a V-block provides a simple and dependable means of supporting round workpieces without unwanted rotation or shift.

Related Measurement Solutions

Digital Height Gauges

Combine V‑blocks with digital height gauges for quick, repeatable measurements on shafts and round components.

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Granite surface plates

Position magnetic V‑blocks on granite surface plates to secure cylindrical parts for runout and diameter checks.

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Industries Used In - Magnetic V-Block -

A coordinate measuring machine (CMM) probe performing precise dimensional inspection inside the bore of a machined aluminium component.

Precision Engineering

Holding cylindrical and irregular workpieces securely for precision grinding, milling, drilling and marking operations, without complex mechanical clamps.


Precision engineering companies use magnetic V‑blocks to support shafts, pins and round parts on machines and surface plates, improving access and repeatability during high‑accuracy machining and inspection.

A Renishaw motorised CMM probe head performing high-precision inspection on a grooved metal component.

Metrology & Quality Inspection Labs

Clamping round components on surface plates and comparators for dimensional checks, runout measurement, concentricity checks and gauge setting.


Metrology and inspection labs use magnetic V‑blocks as quick, repeatable workholders for cylindrical specimens, ensuring stable positioning during precision measurement and reporting.

A technician wearing a yellow hard hat and safety glasses using a calliper to check the precise inner dimensions of a machined metal component.

Machine Shops and Toolrooms

Supporting shafts, mandrels, tools and fixtures during grinding, light milling, drilling and layout work on general-purpose machine tools.


Machine shops and toolrooms rely on magnetic V‑blocks for fast, flexible workholding on milling machines, grinders and drill presses when working on round or profiled parts.

Unfinished car bodies moving along an automated assembly line track inside an automotive manufacturing facility.

Automotive Manufacturing

Holding camshafts, crankshafts, transmission shafts, pins and bushings for inspection, light machining and marking of critical features.


Automotive manufacturers use magnetic V‑blocks on surface plates and in grinding and machining cells to improve setup speed and stability when working with rotational components.

A female aerospace technician in blue overalls inspecting a complex aircraft jet engine component.

Aerospace Manufacturing

Clamping precision shafts, pins, actuators and small cylindrical aerospace parts for high‑accuracy grinding, drilling and dimensional verification.


Aerospace manufacturers use magnetic V‑blocks where secure but easily adjustable holding of ferrous round components is required to meet tight tolerance and traceability demands.

FAQs

How do magnetic V‑blocks differ from standard (non‑magnetic) V‑blocks?

A standard V‑block relies on mechanical clamps or straps to secure the workpiece in the V‑groove, which takes time to position and can obstruct access for indicators or tooling.

 

A magnetic V‑block uses an internal permanent magnet or electromagnetic circuit, switched on or off via a knob or lever, to clamp the workpiece without external straps. This gives much faster setup, unobstructed access for probes and cutting tools, and easier rotation of the part for roundness and runout checks while still maintaining secure support.

Size selection is driven by the diameter and length of the cylindrical workpieces you need to support, and the available space on your machine or surface plate.

 

Typical magnetic V‑blocks cover clamping ranges from around 3–25 mm up to 10–150 mm, with pull capacities from 25 kg to over 175 kg depending on block size. As a guide, choose a block where the workpiece diameter falls comfortably within the specified clamping range, and where the block footprint matches your machine or surface plate without overhang. For longer shafts, matched pairs are recommended to support both ends.

Quality magnetic V‑blocks are manufactured from hardened and ground steel with V‑angles held at 90° ± 5 arc‑minutes, and flatness, squareness and parallelism typically within 5–10 µm on standard sizes.

 

This makes them suitable for high‑precision inspection tasks such as checking roundness, runout and concentricity on surface plates or grinders, provided they are used within their specified load limits and with a clean, flat supporting surface.

Calibration intervals depend on usage intensity and quality requirements. In many QA environments, V‑blocks and magnetic V‑blocks used as inspection fixtures are calibrated on an annual basis, with more frequent intervals (6–12 months) in high‑use or regulated sectors. Calibration typically verifies V‑angle tolerance, flatness, squareness and parallelism using a surface plate, dial indicator and master cylinders or a CMM, with results recorded on a calibration certificate.

 

Any block that shows visible damage, wear on support faces, or inconsistent readings against a known reference should be removed from service and checked immediately.

 Good practice includes:

 

  • Cleaning: After use, remove swarf and abrasive dust, then wipe all working surfaces and the V‑groove with a soft, lint‑free cloth. Keep the bottom face and V‑groove free from chips that could affect seating or clamping.
  • Corrosion protection: Lightly oil exposed steel surfaces to prevent rust, especially if used with coolant or in humid environments.
  • Magnet care: Turn the magnet off when not in use and avoid grinding directly on the block unless it is designed for that purpose. Do not overheat the block. Excessive heat can permanently reduce magnetic strength.
  • Storage: Store in a dry cabinet or drawer, ideally in pairs, with protective packing between blocks to prevent damage to ground faces and the V‑groove.

Regular visual inspection and prompt removal of minor burrs help maintain both holding performance and metrology accuracy.