Fatigue cracks

Sketch of a fatigue crack with length 2c; depth a and specimen thickness t.

About edmnotch.com

The company behind EDMnotch.com is Assmann Verspaningstechniek. The company was founded in 1985 as a precision tool room and started EDM-machining in 1990.
Nowadays the company is a top notch supplier of the NDT industry by machining EDM notches into custom calibration blocks.