Undercut anchors

KEIL Undercut Anchor

KARL Undercut Anchor

KARL® Undercut Anchor KH CH (Hexagon socket bolt)

Anchor sleeve and stepped threaded bolt with hexagon socket A4 and nut with locking ratchets made of stainless steel quality A4

D1 = drill hole Ø
D2 = undercut Ø
SW = shaft spanner gap
XA = anchor hex

further dimensions on request

Product information

  • The KARL® undercut anchor consists of a self-cutting anchor sleeve, a hexagon socket bolt and a locking nut.
  • The anchor sleeve, compressed in the lower area, is inserted into the cylindrical drill hole.
  • Rotating, the anchor creates its own undercut. This is done by inserting the pin of the setting tool clamped in the cordless drill in a path-controlled manner. The anchor is driven by means of the hexagon socket of the setting tool. The anchor sleeve is expanded to the initial dimension. Thus, it always lies fully against the self undercut area of the drill hole of the facade panel.
  • With slight pressure on the plate holder (to lock the anchor), the threaded bolt is screwed in. The locking teeth of the nut dig into the plate holder as a screw lock. After assembly, the anchor is seated in the undercut hole without expansion pressure, i.e. the bracket can still be turned with a certain amount of force.
  • Due to the adjusted thread matched to the anchor length, the screw-in depth always fits and the assembly is process-safe.
  • Drill hole, anchor sleeve and hexagon socket bolt must be matched to the desired insertion depth and the selected plate holder. Only the use of matching parts makes assembly quick, easy and safe.
  • Screw on soffit angle and grooved washer with nut.
  • KARL® undercut anchors are externally monitored.


  • Fiber concrete
  • Fiber cement
  • High-pressure laminate (HPL)
  • Compressed fiberboard

We would be happy to test the usability of our undercut anchor in your material as well.

Instructions of use

  • Application according to approval and KARL® installation instructions for anchors.

Packaging unit

500 pieces

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Depth control guide

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