Concrete screw Koelner/Rawlplug M 7.5x35 mm with internal M8 thread, pack 10 is a mechanical fastener designed for anchoring fixtures and components into solid concrete. The fastener combines a metric M7.5 shank with an internal M8 thread, allowing bolts or threaded rods to be installed after the screw is fixed in the base material. Supplied in a pack of 10, this product is intended for construction, installation and repair tasks that require a threaded connection in concrete without the need for chemical anchors.
Advantages
The product provides a direct threaded connection in solid concrete, enabling strong mechanical retention and straightforward installation. Its internal M8 thread permits the use of standard bolts or threaded rods for connecting fixtures. Supplied in a small pack of 10, the screws are practical for targeted jobs or maintenance tasks and reduce the need to store large quantities of different anchor types.
Suitable for
- Fixing brackets, plates and small frames to solid concrete
- Installing threaded connections where an internal M8 thread is required
- Repair and retrofit work in buildings and infrastructure
- Light to medium duty mechanical anchoring in structural concrete
When it may not be suitable
This concrete screw is intended for use in solid concrete; it is not designed for use in hollow masonry, aerated concrete blocks, or lightweight block materials without prior verification of suitability. For very high load structural connections, chemical anchors or larger-diameter mechanical anchors may be more appropriate depending on engineered load requirements.
Key specifications
- Shank diameter: M 7.5 mm
- Embedment length: 35 mm
- Internal thread: M8
- Material: steel (zinc-plated or corrosion-protected finish as typical for mechanical concrete screws)
- Package quantity: 10 pieces
How to use
Drill a correctly sized hole in solid concrete using a hammer drill and a masonry bit suitable for the shank diameter and embedment depth. Clean the hole of dust and debris before inserting the concrete screw. Drive the screw into the drilled hole until the head or collar seats against the fixture surface. After the screw is installed, fit an M8 bolt or threaded rod into the internal thread and tighten to achieve the required clamping force. Follow recommended drilling diameter, hole depth and torque values from applicable technical guidelines for reliable performance.
What to consider before purchase
- Confirm the base material is solid concrete rather than hollow block or aerated concrete
- Verify that an internal M8 thread meets the required connection and load needs
- Check embedment depth and drill bit size compatibility with your installation tools
- Consider corrosion protection requirements based on environment and exposure
Usage recommendations
Use appropriate personal protective equipment (eye protection, gloves) and a correctly sized hammer drill with a suitable masonry bit. Clean drilled holes thoroughly before insertion and use calibrated torque control when tightening the M8 fastener to avoid overloading the concrete screw or the base material.
