Expert Witness

Jeffrey Badger, Ph.D.

The Grinding Doc

Dr. Badger has served as an expert witness in numerous legal cases. He has testified in court and in depositions. He has performed tests and examinations to evaluate the root causes of wheel failure, to determine grinding-wheel quality with respect to the risk of in-service failure, to demonstrate typical failure scenarios and safety risks, and to determine the presence of “grinding burn” in ground workpieces.

Dr. Badger investigates each case individually with absolute impartiality. He does not accept any appointments where there is a conflict of interest.

In addition, he has partnered with Dr. Eric Constans, Professor at Rose-Hulman Institute of Technology, to build a lab with the sole purpose of causing grinding wheels to fail and investigating the failure. Visit for more information.

Contact Dr. Badger for a preliminary discussion on the particular case.


Common relevant subjects:

Thermal damage and “grinding burn”: High temperature during grinding can result in thermal damage to the workpiece – colloquially known as “grinding burn” – which typically manifests itself as residual tensile stresses and/or a phase change in the material. Thermal damage can cause reduced fatigue life of the ground component or even immediate cracking. Dr. Badger has worked extensively with thermal damage and has served as an expert witness in cases involving workpieces that have suffered thermal damage.

Wheel failure, grinding safety: Grinding wheels sometimes break. This has implications in terms of safety, eye protection, guarding, maximum safe operating speed, “overspeed testing” before shipment, causes of failure, etc. Dr. Badger has worked in several cases involving failure of grinding wheels.

Intellectual property: What constitutes a trade secret in the grinding industry, new and novel  developments in grinding machines, abrasives and grinding processes.


Dr. Badger’s Grinding Doc column on how thermal damage affects fatigue life in cyclically loaded ground workpieces.


Video of wheel-failure testing from Dr. Badger’s previous expert-witness work on failure of grinding wheels in angle-grinders.