Hilti DX 351 M&E Manual page 35

9.2 Problems with fasteners
Malfunction
Fastener driving depth varies
The fastener bends
The fastener is not driven
flush
Concrete spalling
Damaged fastener head
The nail doesn't penetrate
deeply enough
The fastener doesn't hold in
the base material
Fastener breakage
(shear breakage)
Fastener breakage
(with deformation)
*332581*
Possible cause
Incorrect piston position
Piston bounce because driving
energy is too high.
Hard material (steel, concrete).
Hard and/or large aggregates in
the concrete.
A rebar is located just below the
concrete surface.
Wrong fastener.
Wrong power setting.
Hard and/or large aggregates in
the concrete.
A rebar is located just below the
concrete surface.
Hard and/or large aggregates in
the concrete.
Too much driving energy.
The wrong piston has been fitted.
The piston is damaged.
Driving energy too low
The application limits have been
exceeded (very hard material).
The system is unsuitable.
Thin supporting steel (4­5 mm)
Driving energy too low
The application limits have been
exceeded (very hard material).
Driving energy too low
332581
Action to be taken
▶ Check piston brake and piston
for wear; replace the compo-
nents as necessary. → page 27
▶ Reduce driving energy.
▶ Turn the adjusting knob for
driving energy to increase
driving energy.
▶ Use a shorter nail.
▶ Use a nail with a higher
application limit.
▶ For concrete: Use the DX-Kwik
method (predrilling) → see the
'Direct Fastening Technology
Manual'.
▶ Use the DX-Kwik method
(predrilling).
▶ Drive the fastener at a different
position.
▶ Match the length of the fastener
to the thickness of the compo-
nent.
▶ Change the energy setting on
the fastening tool.
▶ Use the DX-Kwik method
(predrilling).
▶ Drive the fastener at a different
position.
▶ Use the DX-Kwik method
(predrilling).
▶ Turn the adjusting knob for
driving energy to reduce driving
energy.
▶ Make sure that the correct
piston / fastener combination is
used.
▶ Change the piston.
▶ Increase driving energy.
▶ Use a more powerful cartridge.
▶ Use a nail with a higher
application limit.
▶ Use a more powerful system,
e.g. DX 6.
▶ Use a different energy setting.
▶ Use a nail suitable for thin
supporting steel.
▶ Increase driving energy.
▶ Use a more powerful cartridge.
▶ Use a more powerful system,
e.g. DX 6, with corresponding
suitable fasteners.
▶ Increase driving energy.
▶ Use a more powerful cartridge.
English 29