• No.3 self-drilling point cuts its own hole in steel. No pre-drill, so you fix faster.
• Drills light section steel up to 5.0mm thick. Covers standard purlins and rails.
• Hex head driven with an 8mm socket. Sits square and won't cam out.
• 5.5mm diameter, fully threaded 60 degree self-tapping thread for a firm grip.
• Case and core hardened carbon steel. Hard tip to drill, tough core to hold torque.
• Exterior Silver Organic finish, 500 hour salt spray, Corrosion Rating 3 for outdoor use.
• Fire Classification A1 and approved to BS EN 10666 (DIN 7504).

Use these for fixing metal roofing and cladding sheet onto light gauge steel:

• Fixing profiled roofing sheet to steel purlins on agricultural and industrial buildings.
• Securing wall cladding to steel rails and side sheeting.
• Sheet-to-steel metal construction work where the section is up to 5.0mm thick.
• Any exterior steel fixing that needs a corrosion-rated screw and no pre-drilling.

These are a metal-to-metal fixing. If you're going into timber rather than steel section, you'll need a different screw.

• Brand: TIMCO
• Material: Case & core hardened carbon steel
• Finish: Zinc & Clear (silver BZP)
• Head type: Hex (8mm socket)
• Point: Self-drilling No.3 (drills steel up to 5.0mm)
• Thread: Self-tapping, fully threaded
• Diameter: 5.5mm
• Sealing washer: 16mm EPDM (included)
• Substrate: Roofing sheet to light section steel, max 5mm
• Approval: BS EN 10666 (DIN 7504)
• Pack: Box

What's the difference between self-drilling and self-tapping?

A self-drilling screw has a drill point on the tip, so it bores its own hole as you drive it. A plain self-tapping screw cuts a thread but needs a pilot hole first. These TIMCO screws do both. The No.3 point drills the hole and the 60 degree thread taps and grips, all in one go.

How thick a steel section can they drill?

Up to 5.0mm. That's the maximum for the No.3 drill point. As long as your purlin or rail is 5.0mm or under, you can drive straight in with no pre-drilling.

Do I need a washer with these?

This version comes with no washer. For a weathertight roof or clad wall you'll normally want a bonded EPDM washer under the head to seal the fixing. Add one separately, or pick the washered version of this screw if you'd rather have it built in.

What speed should I drive them at?

Between 1,000 and 1,800 RPM. Let the drill point do the cutting and don't lean on it too hard. Push too fast and you can burn the tip before it bites, especially on thicker section.

What socket do I need to drive them?

An 8mm hex socket. Use a nut driver or a socket bit in your impact driver and keep it seated square on the head.

Are they alright for outdoor use?

Yes. The Exterior Silver Organic finish has passed 500 hours of salt spray and carries a Corrosion Rating 3, which suits urban and industrial areas with a low salt atmosphere. They're made for external steelwork like roofing and cladding.