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7HF Black Magnetic Ink • Fidgeon

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7HF Black Magnetic Ink

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Product Information

Magnaflux 7HF Black Magnetic Ink

Magnaflux 7HF Black Magnetic Ink is an oil based MPI ink available in both aerosols and bulk. The ink is used in conjunction with suitable magnetising equipment to locate fine surface and slightly subsurface discontinuities in ferrous materials. Typical defects found include shrink cracks, welding defects, grinding cracks, quenching cracks and fatigue cracks. 7HF gives clear black indications when viewed in daylight.

7HF is a highly sensitive oil-based product for nonfluorescent (visible) wet method magnetic particle testing to locate fine and medium discontinuities on finished parts.

This ink provides clear, strong indications due to the heavy buildup of the highly magnetic particles. The convenient aerosol packaging is ideal for field testing, spot inspections and places where bulk processing is impractical and the wide spray pattern makes it easy to cover large areas for faster processing during remote inspections of tubing, piping and large structures.


Maximise indication detection

  • Find indications of all shapes and sizes thanks to the smallest particle on the market
  • Heavy buildup of highly magnetic particles around all leakage fields make for heavy-contrast indications, especially when used with WCP2 (White Contrast Paint)

Convenient to use

  • Inspect in all conditions without the need for darkness or UV lights
  • The visible particles come in a convenient, aerosol format to be easily carried and used in the field

Wide application versatility

  • Inspect a wide range of components without fear of corrosion or specification non-conformance


  • Clear indications under visible light
  • Heavy particle buildup
  • Great particle mobility
  • Protects parts and equipment against corrosion
  • Broad spray pattern provides even surface coverage over large areas
  • Superior surface wetting
  • Very small particle size
  • Works in visible light
  • Oil-based formula
  • Very low toxicity
  • Low odor


Specification compliance

  • AMS 3043
  • ASTM E709
  • ASTM E1444
  • Boeing PS-21201
  • ISO 9934
  • MIL-STD-2132
  • NAVSEA 250-1500-1
  • NAVSEA T9074-AS-GIB-010/271


Defect location: surface and slightly subsurface

Ideal for:

  • Detecting fine and medium discontinuities
  • Field testing
  • Spot inspections
  • In-service inspections
  • Machined parts
  • Light surfaces
  • Difficult to reach areas

Defect examples:

  • Inclusions
  • Seams
  • Shrink cracks
  • Tears
  • Laps
  • Flakes
  • Welding defects
  • Grinding cracks
  • Quenching cracks
  • Fatigue cracks

Instructions for use

Use 7HF with appropriate magnetisation procedure and equipment. For best results, all components, parts, or areas to be tested should be clean and dry prior to testing to provide an optimal test surface and reduce particle suspension contamination.

  1. Use in a well ventilated area
  2. For best results, apply the white contrast paint (we recommend WCP2) before the 7HF to improve contrast and inspection sensitivity
  3. Shake 7HF aerosol can well before use and occasionally during application to ensure suspension uniformity and concentration
  4. Hold the can 7 to 9 inches (18 to 24cm) from the area to be tested
  5. Using the continuous or residual application method, spray particle suspension over the test area until it is completely covered
  6. Inspect under visible light

To verify particle concentration, perform a sensitivity check using a known test standard prior to inspection


All components, parts, or inspection areas must be properly demagnetised before cleaning to ensure easy particle removal. Cleaned parts may be treated with a temporary film protective coating if longer corrosion protection is required


Store in a well ventilated area away from magnetising equipment and heat sources. Product age, exposure to elevated temperatures, and/or exposure to a strong magnetic field may adversely affect particle redistribution. Refer to Safety Data Sheet for additional storage instructions



Additional information


Package Size

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