• Self-drilling point. Drills straight through light gauge steel up to 3.0mm, so you skip the pilot hole.
• 60 degree self-tapping thread, fully threaded. Bites hard and pulls the board tight to the frame.
• Countersunk wafer head with ribs under the head. It cuts its own seat and sits flush in the board, no separate countersink needed.
• Phillips PH2 recess. A PH2 driver bit comes in the box.
• Exterior Plus finish. A silver/grey organic plating rated to 1,500 hours salt spray. It handles damp and mildly corrosive areas.
• Carbon steel body, Corrosion Rating 3. Suited to urban and industrial areas with a low salt atmosphere.
• Fire Classification A1. The top non-combustible rating.
• 4.2mm diameter. Two lengths to choose from, 4.2 x 32mm and 4.2 x 42mm.

• Fixing cement board and fibre-cement board to steel dry-lining frames.
• Metal stud partitions and stud walls lined with cement board.
• Tile backer board onto light section steel before tiling.
• Exterior and damp areas like bathrooms, wet rooms and utility spaces where a standard screw would rust.

• Brand: TIMCO
• Material: Carbon Steel
• Finish: Exterior Plus (silver/grey organic plating)
• Head: Countersunk Wafer, self-countersinking with ribs under the head
• Recess: Phillips PH2 (bit included)
• Point: Self-drilling, drills light section steel up to 3.0mm
• Thread: 60 degree self-tapping, fully threaded
• Diameter: 4.2mm
• Lengths: 4.2 x 32mm, 4.2 x 42mm
• Substrates: Cement board and fibre-cement board fixed to steel frames
• Max drilling capacity: 3.0mm steel
• Salt spray resistance: 1,500 hours
• Corrosion Rating: 3 (urban and industrial, low salt atmosphere)
• Fire Classification: A1
• Recommended RPM: 1,800 to 2,500

Do I need to pre-drill for these screws?

No. The self-drilling point cuts its own hole through the steel frame as you drive it. That works on light section steel up to 3.0mm thick. Go thicker than that and the point won't get through.

What's the maximum steel thickness they'll drill?

3.0mm. They're built for light section steel dry-lining frames. For heavier steel you'll need a heavy-duty self-drilling screw or a pre-drilled pilot hole.

Can I use them outside?

Yes. The Exterior Plus silver organic plating is rated to 1,500 hours salt spray and carries Corrosion Rating 3. That covers damp interiors and exterior spots in urban or industrial areas with a low salt atmosphere. For coastal or heavy salt exposure, step up to a higher corrosion rating.

What board types do they suit?

Cement board and fibre-cement board fixed onto a steel frame. That takes in tile backer boards and general cement particle boards used on metal stud partitions.

What drill speed should I run?

Keep the driver between 1,800 and 2,500 RPM. Too slow and the point struggles to drill the steel. Too fast and you can burn the tip before it bites.

Do I still need a countersink bit?

No. The wafer head has ribs underneath that cut their own seat, so the head pulls flush into the board on its own.