C2 Tongue-Fix TX Reduced Countersunk Screw 3.5x45mm Box 200

The C2 Tongue-Fix is a reduced countersunk wood screw built specifically for fixing tongue and groove floorboards and timber panelling. At 3.5 x 45mm with a TX drive, these countersunk wood screws sit flush at the tongue, keeping the fixing hidden once the next board drops into place. The result is a clean, concealed fix with no visible fastener heads to sand over or fill.

Standard countersunk screws were not designed for this job. They sit too high, they split timber at the narrow tongue, and they drag badly without lubrication. The C2 Tongue-Fix addresses all three problems in one fastener.

What Makes the C2 Tongue-Fix Different from Standard Countersunk Wood Screws

The reduced head is the key feature. It sits snugly within the tongue without breaking through the shoulder of the board, which would compromise the joint. The plain shank beneath the head lets the screw pull the board tight to the joist or batten without the thread fighting you from both sides — no clamps needed, just drive and move on.

The dual-angle thread is cut for high pull-out resistance in timber, so once the board is down it stays down. Floors flex and seasonal movement happens, but these screws hold their position through it. The patented twin-cut point picks up quickly without wandering, which matters when you are working your way across a floor on your knees with a cordless driver in hand.

The polymer lubricant coating is worth noting. It reduces insertion torque by up to 52% compared to an uncoated screw, which means less effort per drive and far less risk of cam-out or snapped screw heads. It also provides rust protection rated at up to 20 times longer than standard zinc plating, so these screws are suitable for environments where moisture is a factor, including solid timber floors over underfloor heating or in conservatories.

Drive Type and Box Quantity

The TX (Torx) drive offers better torque transfer than a Pozidriv and is considerably less likely to strip under load. If you are driving 200 screws across a floor run, the drive type matters — TX stays engaged and lets you work at pace without reworking stripped heads. The box contains 200 screws, with a larger tub of 350 also available if the job warrants it.

For tongue and groove flooring installations, the C2 Tongue-Fix 3.5 x 45mm gives a clean, fast, and reliable fix that sits within the tongue and disappears when the floor is laid. Fewer callbacks, less finishing work, and a floor that looks the way it should.