Undercut anchors ( ☛ see expert knowledge entryg) are used for the invisible fastening of façade panels in rear-ventilated façades (VHF). This entry in cooperation with KEIL Befestigungstechnik describes the installation instructions for undercut anchors on façade panels.
The general entry on the functionality of undercut anchors and the undercut technique can be found here.
façade panels are to be provided with undercut holes on the back, under workshop conditions, using KEIL system tools.
The KEIL system tool consists of the KEIL façade drill, the KEIL drill head and the undercut drill, e.g. KEIL hand drill, KEIL bench drill or automatic drill with KEIL drill head.
Drilling and undercutting
Image: Drilling and undercutting - KEIL Befestigungstechnik
The undercut hole is produced in a single operation (cylindrical drilling 1 and undercutting 2).
Only if there is an exactly undercut drill hole 3 is it possible to install the undercut anchor in accordance with the regulations. Regular monitoring of the borehole geometry is carried out by the KEIL measuring caliber that matches the setting depth of the armature. With the help of this measuring caliber, the setting depth hS is adjusted and all essential dimensions of the borehole can be checked rationally.
Anchor sleeves and locking tooth screws for fixed clamping thicknesses, e.g. clasps
The undercut anchor consists of an anchor sleeve and a corresponding hexagonal screw.
The drill hole, anchor sleeve and thread length of the screw must be matched to the desired setting depth hS of the undercut anchor and the selected plate holder. Only the use of parts that belong together makes assembly quick, easy and safe.
Assembly process step by step :
1 - The anchor sleeve, which is compressed in the lower area, is inserted into the drill hole together with the prescribed plate holder 4.1.
Image: 4.1.
. The locking toothing of the screw digs into the plate holder as a screw lock.
Image: 5.1.
By screwing in the screw in a controlled manner, the anchor sleeve is widened to the initial dimension so that it rests on the entire surface of the façade panel in the undercut area of the bow hole. After installation, the anchor sits in the undercut drill hole without expansion pressure (i.e. the clasp can still be rotated with a certain amount of force).
Note: If the right screw is used with a defined clamping thickness, the screw-in depth is always right! Installation is then quick, easy and safe. Likewise, the exact screw-in depth of the KEIL plug-in anchors is guaranteed by the system. The screwed-in part must be flush with the anchor sleeve at the front.
Attention: Before each installation, a test assembly must be carried out to check whether the screwed-in part is flush with the anchor sleeve at the front.
Anchor sleeves and threaded screws for variable clamping thicknesses
The undercut anchor consists of an anchor sleeve and an associated threaded screw.
The drill hole, anchor sleeve and threaded pin must be adjusted to the desired setting depth hS of the undercut anchor. Only the use of parts that belong together makes assembly quick, easy and safe.
Installation process:
1 - Insert the anchor sleeve, compressed in the lower area, into the undercut drill hole 4.2.
Image: 4.2.
3 - Hold the anchor sleeve with an open-end wrench and screw in the threaded pin with the screw-in screw as far as it will go - loosen the screw-in handle.
4 - Check Measure Ü 5.2.
Image: 5.2. Assembly process - KEIL fastening technology
5 - Screw on plate holder with nut.
By screwing in the threaded pin a controlled way, the anchor sleeve is widened to the original dimension so that it rests on the entire surface of the façade slab in the undercut area of the drill hole. After installation, the anchor sits in the undercut drill hole without spreading pressure.
Note: The correct screw-in depth is guaranteed when using the appropriate assembly tool, the KEIL screw-in screw, and by observing the assembly process. This means that the appropriate overhang Ü is automatically observed.
Attention: Before each installation, a test assembly must be carried out to check whether the screwed-in part is flush with the anchor sleeve at the front and whether the appropriate assembly tool is used.
With KEIL plug-in anchors, the exact screw-in depth is also guaranteed by the system (anchor type CA).
Image: Borehole geometry - WEDGE fastening technology
Legend
D1 = Borehole diameter (Ø 7 mm)
D2 = Undercut diameter (≥ Ø 9 mm)
h = Plate thickness (from 6 mm)
hs = Setting depth of the undercut anchor
xA = Anchor hexagon (3 mm)
xZ = Thickness of the plate holder (clamping thickness)
Source : KEIL Befestigungstechnik
In cooperation with :
