Hilti FX 3-A Operating Instructions Manual page 42

2. Select the appropriate surfacing tool for working on the surface to be prepared.
Materials
FX 3­ST d14 surfacing tool for the following base metals:
- uncoated carbon steel
- weldable primer on steel, coat thickness up to 25 μm
FX 3­ST d20 surfacing tool for the following base metals:
- non-weldable primer on steel
- weldable primer on steel, coat thickness 25 μm and thicker
- galvanized steel
- duplex-coated steel
- multi-coated steel
Maximum coating thickness 1 mm
WARNING
Hazard due to inadequate surface preparation. If the surface was inadequately prepared, a subsequent
weld is substandard and the stud's load-bearing ability is reduced!
▶ Weld the stud within 2 hours after surface preparation.
▶ Before every welding operation, always check that the surface is correctly prepared.
3. Remove the coating with the surfacing tool. Apply firm contact pressure to the drill / driver.
Technical data
Contact pressure
Materials
Hilti SF 8M­A22 cordless screwdriver, 3rd gear, speed 1250 rpm, setting for drilling
▶ The surface and the ring produced around the prepared area must be free of all traces of coating
material and/or contaminant. Remove all residues and contaminants caused by the surfacing
operation.
Comply with the operating instructions of the drill / driver.
As a general rule, the tool-specific operating instructions of the cordless drill / drivers apply. In this
special application for surface preparation with the surfacing tools in the FX 3-A system, the drill /
driver can also be held with the other hand at the back of the drill / driver.
5.7 Connecting ground clamp
▶ Connect the ground clamp to an uninsulated point on the workpiece or to a stud welded beforehand.
Comply with the requirement for minimum spacing between the stud to be welded and the ground clamp.
When welding on walls, always position the ground clamp below the weld position.
Technical data
Minimum distance between the stud to be welded and the
ground clamp
If the workpiece is coated or offers no uninsulated point for connection of the ground clamp, use
the magnetic foot on a surface prepared beforehand. → page 32
5.7.1 Positioning magnetic foot
Position the magnetic foot for the first stud only. For all subsequent studs, connect the ground clamp to a
stud welded on beforehand.
1. To create an uninsulated point on the workpiece, prepare the workpiece in the same way as for welding
a stud. → page 31
Ideally, this means preparing the workpiece at a point where a stud is going to be welded into
place later on.
32 English
9
10
≥ 20 kg
10 cm
2302408
*2302408*