In addition to being manufactured from the right material quality using the right production method, the claws of LMC's GK couplings are tested for mechanical strength by means of an impact test. Above the accepted pressure limit, GK coupling claws may distort, although this is impossible under normal working conditions when both parts of the GK coupling are connected.

However, GK claws are often dropped by operators, which can result in fractures or even claw breakage. Following impact test, LMC's GK coupling claws show no sign of fracture of breakage.