Tndustrial sledgehammers are used throughout JCL Indus-1 tries, most having a 15-pound head made of AIS11060 steel. To reduce tool replacement costs, the company machine shop periodically gathers hammers with heavily deformed (mushroomed) heads and grinds off the deformed segment.
A reground hammer was returned to use. Upon striking a metal plate, a chip flew from a corner of the hammer head and lodged in the eye of a nearby worker. A lawsuit resulted. Subsequent investigation revealed that the heads of new hammers had a bulk hardness between Rc44 and 55. The chip, however, had a hardness of approximately Rc65 on the surface where it fractured from the hammer. Inspection of the other hammers in the shop revealed numerous chipped regions. All of the chips, however, were on redressed hammers.
1. What do you suspect might be the problem?
2. How might you prove your suspicions?
3. How would you alter the procedures or policies of JCL Industries to eliminate a possible recurrence, yet minimize expense?