Research Area

Primer & Chemical Surface Treatment

Mandrel Bending Test
– with Conical Mandrel –

The mandrel bending test determines a characteristic value for the elasticity, adhesive strength and elongation of a cured coating under bending stress.
A coated sheet is bent using a lever around a conical mandrel with a diameter of 3.2 to 38.1 mm. The resulting cracks usually start at the thinner end of the mandrel and continue towards the thicker end.
The maximum crack length is read on the scale and the associated mandrel diameter is determined. The size of the bending diameter, where no changes are visible yet, corresponds to the result of the test.
With the conical mandrel bending test, a large range of different bending radii can be recorded within one test.

Testing Standards:

  • ASTM D 1737 85
  • ASTM D 522
  • DIN 53150
  • DIN EN ISO 1519
  • DIN EN ISO 6860


Application Examples:

  • Pretreatment testing
  • Quality assessment of primers
  • Comparison of curing conditions
  • Evaluation of elasticity, adhesive strength and elongation of coatings
  • Definition of possible bending radii
  • Determination of the mechanical strength of resistant varnishes and similar coatings  

Please do not hesitate to contact us for questions and further information about our R&D and services offered.



BYK Gardner GmbH



Dr. Joerg Leuthaeusser

Head of Department
Primer and Chemical Surface Treatment

Phone: +49 3641 2825 48