TM 5-3805-281-10
TYPICAL TOOL FAILURES
Misalignment or Pry Break
The bending stress exceeds the materials strength and the tool
snaps. Caused by working at an incorrect angle or using the
tool for mechanical leverage. The failure usually occurs near
the tool bushing's front face. This failure can also be caused
by the breaker slipping while hammering at angles not
perpendicular to the surface of the material being broken.
The failure type is a brittle type and typically has a lip
formation.
Seizing in the Tool Bushing
Strong side loading and striking the tool at the same time
causes the tool and bushing surface to be damaged. This
failure is cause by incorrect or insufficient lubrication. The
failure generally occurs in the front tool bushing area. The
failure type is a fatigue fracture starting at the surface of
the tool.
Blank or Dry Firing
Occurs when the working end of the tool is not in proper
contact with the material being broken. The failure can also
occur when breaking through the material and the breaker
strikes the tool a last time. When struck without resistance at
the working end the tool , the tool stops abruptly when it is
stopped by the retainers instead of the material. This results
in breaking and deformation in the retaining groove.
Mechanical Damage on the Tool"s Surface
This is caused by heavy scratching on the tools surface. The
failure usually occurs outside the tool bushing. The failure is
generally a fatigue type fracture.
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