Cutting Metal; Cutting Masonry And Concrete - Makita DPC 6400 Manuel D'instructions Et De Sécurité

Cutting metals
IMPORTANT!
Always wear approved respiratory protection!
Materials that can release toxic substances may be cut only
after notifying the proper authorities and under their supervi-
sion or that of a person appointed by them.
CAUTION!
The rapid rotation of the cutting disc heats metal and melts it
at the point of contact. Swing the guard as far down as
possible behind the cut (19) in order to direct the stream of
sparks forward, away from the operator (fire hazard).
- Determine the direction of cutting, mark the cut and apply the
disc to the material at moderate speed, to cut a guide groove
before going to top speed and applying more pressure to the
Power Cut.
- Keep the disc straight and vertical. Do not tip it, as this can break
it.
- The best way to get a good, clean cut is to pull or move the
Power Cut back and forth. Do not simply press the disc into the
material.
- Thick round stock is best cut in stages (20).
- Thin tubing and pipes can be cut with a simple downward cut.
- Cut large-diameter pipes as for round stock. To prevent tipping
and for better control, do not let the disc sink too deeply into the
material. Instead, always cut shallow around the whole piece.
- Worn discs have a smaller diameter than new discs, so that at
the same engine speed they have a lower effective circumfer-
ential speed and therefore do not cut as well.
- Cut I-beams and L-bars in steps; see Figure 21.
- Cut bands and plates like pipes: along the wide side with a long
cut.
- When cutting material under stress (supported material or
material in structures), always make a notch in the thrust
(pressure) side, and then cut from the tension side, so that the
disc does not lock in. Secure cutoff material from falling!
CAUTION!
If there is a chance that the material is under stress, be
prepared for it to kick back. Make sure you can get out of the
way if you have to!
Be particularly careful in scrap-metal yards, junkyards, at
accident sites, and with haphazard piles of material. Precari-
ously balanced pieces or pieces under stress can act in
unpredictable ways, and may slide, jump out, or burst. Se-
cure cutoff material from falling! Always exercise extreme
caution and use only equipment that is in perfect working
order.
Observe the accident-prevention rules and regulations of
your employer and/or insurance organization.

Cutting masonry and concrete

IMPORTANT!
Always wear approved respiratory protection!
Asbestos and other materials that can release toxic sub-
stances may be cut only after notifying the proper authorities
and under their supervision or that of a person appointed by
them. When cutting prestressed and reinforced concrete
piles, follow the instructions and standards of the responsi-
ble authorities or the builder of the structural member.
Reinforcement rods must be cut in the prescribed sequence
and in accordance with applicable safety regulations.
NOTE:
Mortar, stone, and concrete develop large quantities of dust
during cutting. To increase the lifetime of the cutting disc (by
cooling), to improve visibility, and to avoid excessive dust crea-
tion, we strongly recommend wet cutting instead of dry cutting.
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