The Jerk Test

-Test for flexibility and adhesion strenght of the enamel coating of the wire

Why jerk Test is important!

A jerk test of enamelled wire is a mechanical test used to assess both the flexibility and the adhesion strength of the enamel coating to the wire itself. This test is particularly important for enamelled (magnet) wires because the enamel serves as electrical insulation, and it must remain uniformly adhered during handling, winding, and operation.​

To get specific information of the Jerk Testers, please follow link for datasheets:
JTM, JT Jerk tester

Purpose and Method

• The jerk test checks how well the enamel sticks to the copper (or aluminum) wire and how flexible the wire is after coating.

• In the test, a piece of enamelled wire is rapidly "jerked," typically by a specified mechanical device, and then observed under magnification for any signs of enamel peeling or cracking.​

• Wires that fail the jerk test may show the enamel coming off or exposing the bare conductor after flexing, indicating a risk for electrical failure in practical applications.​

• According to standards like IEC 60851-3 and JIS C 3216-3, this test is usually applied to enamelled round wires with a nominal conductor diameter up to and including 1.00 mm.

Application in Industry

• Ensuring proper enamel adhesion and flexibility helps prevent short circuits, insulation failure, and premature breakdown in electrical machines, transformers, and coils.​

• The jerk test is often performed alongside other tests such as mandrel winding, stretching, and peel tests to provide a complete profile of wire quality.​

In summary, the jerk test is a standardized quality control method designed to verify both the continuity and robustness of the enamel insulation layer on magnet wires, helping ensure safe and reliable performance in electrical applications.​

 Please contact our sales department for more information.