Product Data Sheet – BYCOTEST 103

Ready-to-use Visible Magnetic Ink

Chemical product icon - visible magnetic

General Description

BYCOTEST® 103 is an oil-based, ready-to-use black ink that gives clear black indications when viewed in daylight.


Used in conjunction with suitable magnetising equipment, 103 will locate medium-fine surface and slightly subsurface defects in ferrous materials. Typical defects found include shrink cracks, welding defects, grinding cracks, quenching cracks and fatigue cracks.


103 consists of a suspension of black magnetic particles in a high-flash, low-odour petroleum distillate.


  • Ready to use
  • High sensitivity
  • Clear indications

Typical Properties (not a specification)

Property 103
Flash point > 93°C (bulk product)
SAE sensitivity 6 – 7
Viscosity at 38°C 2.5 mm²/s
Particle size (mean) 0.2 – 2.0 µm
Settlement volume (1 hour) 1.2 – 2.4 ml
Sulphur content < 200 ppm
Halogen content < 200 ppm
Storage temperature 10°C to 30°C
Usage temperature -10°C to 50°C

Like all Magnaflux materials, BYCOTEST 103 is closely controlled to ensure batch-to-batch consistency, optimum process control and inspection reliability.

Specification Compliance

Specification 103
AMS3043 (Aerosols only) Yes
ASME B & PV Code, Sec V Yes
EN ISO 9934-2 Yes
GOST R ISO 9934-2-2011 Yes

General Method of Use

Clean the component before testing to reduce the risk of contamination and provide a suitable test surface.

If the test surface is a dark colour, apply a thin coating of a suitable white contrast paint – such as 104A or 104Plus – to provide a better contrasting background.

Shake the aerosol can for 30 – 60 seconds initially to ensure that the ink is mixed thoroughly. You will need to shake the can repeatedly during use.

Spray the ink onto all surfaces of the component. The indications will be formed during the application of a magnetising current.

After inspection, the components should be properly demagnetised before cleaning.

Recommended Products

Product type Product name(s)
Cleaner/pre-cleaner BYCOTEST C5, C10
Contrast paints BYCOTEST 104A or 104plus

Health & Safety

Read the relevant Safety Data Sheet for this product before use.


Download this Product Data Sheet as a PDF

Part number 008A171
x 10

Packaging icon: 400 ml aerosol can