The Koelner/Rawlplug concrete screw M 7.5x35 mm with an internal M10 thread is a fastening element intended for direct anchoring into concrete and solid masonry. Supplied as a pack of 10, each screw combines a self-tapping outer thread for cutting into mineral substrates with an internal female M10 thread for accepting bolts or threaded rods. The product is intended for applications where a secure, load-bearing female thread is required without using a separate anchor sleeve.
Advantages
This concrete screw provides straightforward installation into solid concrete and dense masonry, reducing the need for additional anchor components. The integrated internal M10 thread allows direct mounting of equipment and fixtures with standard M10 male fasteners. Being supplied in a pack of 10 makes it convenient for small installation jobs or phased work on site. The screw’s external geometry is designed to create a reliable mechanical interlock with the substrate, delivering dependable holding capacity for appropriate loads.
Suitable for
- Fixing mounting brackets and metal supports to concrete walls and floors
- Securing equipment, enclosures or conduit boxes that require an internal M10 thread
- Small renovation and construction tasks where direct female-threaded anchors are preferred
- Applications in garages, basements, utility rooms and commercial sites with solid masonry
When it may not be suitable
This type of concrete screw is intended for use in solid concrete and dense masonry; it is not suitable for hollow blocks, weak or crumbling substrates, or plaster-only surfaces where the screw cannot achieve the required engagement. For heavy structural loads, dynamic loading, or use in cracked concrete where design-level safety factors are required, consult structural guidance and consider engineered anchors or chemical anchoring systems.
Key specifications
- Screw outer diameter: 7.5 mm
- Nominal screw length: 35 mm
- Internal thread size: M10 (female)
- Material: hardened steel (corrosion protection depends on finish)
- Pack quantity: 10 pieces
How to use
Drill a hole in the concrete or solid masonry using a carbide-tipped masonry bit matched to the screw outer diameter and to the required embedment depth. Clean the hole of dust and debris using a brush or compressed air. Insert the concrete screw into the hole and advance it using an appropriate hex or screw driver/socket until the head is flush or to the specified depth. Then insert an M10 bolt or threaded rod into the internal thread to mount the fixture. Follow manufacturer recommendations for drill diameter, drill depth, and required torque to achieve rated performance.
What to consider before purchase
- Ensure the substrate is solid concrete or dense masonry suitable for direct screw anchors
- Verify required load capacity and whether an internal M10 thread meets the fixture’s needs
- Confirm the screw length and diameter provide sufficient embedment for the intended application
- Check corrosion protection requirements for the installation environment
Usage recommendations
Use a correctly sized carbide masonry drill bit and clean holes thoroughly before installation. Do not use these screws in hollow or weak materials. For critical or safety-related fixings, follow applicable design documents and, if necessary, choose anchors tested for the specific load conditions.
