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Hex Flange Metal Screws

Hex Flange Metal Screws

Hex Flange Metal Screws

Not sure what screw size you have or need?

Two ways to confirm before you order - whichever you already know.

1If you have a screw in hand

Measure across the outside of the thread - not the shank - to get the gauge (a 10g screw measures about 4.8mm). Screw gauges have a wider tolerance than bolts, so treat it as a close match rather than exact. Then measure the length for your head type.

Open the screw gauge sizing chart ›

2If you know the gauge

Every product page carries a Screw Gauge and TPI chart for its range - every gauge links straight to the product. For metal: coarse threads bite and hold thin sheet; fine threads (higher TPI) give more grip in thicker steel.

Self drilling tek screw side profile showing where to measure

Self drilling (tek) screw - gauge is measured across the thread, not the drill point.

Hex flange self drilling screws combine a wide flange head, bonded weather washer and self drilling point in one fastener. They are the default for sheet roofing, walling and metal cladding fastening into purlin and structural steel. The hex head drives with a 5/16" or 3/8" socket for high seat torque without head cam-out.

Also known as: Tek Screw, Roofing Screw, Cyclone Screw, Hex Head Tek, Hex Flange Tek, BRA Screw, Multiseal Screw, Sheet Metal Screw.

The Cyclone range is the BNA hex flange standard - 14g-10 gauge, Tek 4 drill point (BRA / Multiseal designation), full-thread design, lengths from 53mm through 75mm. Galvanised Class 3 or Zinc Yellow Class 4 finish. The pre-installed bonded washer guarantees weather seal at every penetration without site-applied sealant.

GRADES AND MATERIALS

Zinc Yellow (Class 2): zinc plate with a yellow chromate passivation - Class 2 corrosion rating for interior and dry, sheltered work. Galvanised (Class 3, 4, B8 and X9): galvanised and heavy-coated finishes for exterior, structural and coastal exposure - the higher the class, the harsher the environment it suits. Both use a Class-rated steel core for high pull-out and shear strength.

DRIVE AND INSTALLATION

Drive with a 5/16" or 3/8" socket in a powered driver - the AF is published per SKU. Set the driver to seat the head against the cladding so the bonded washer compresses evenly. Don't over-torque - the bonded rubber is the weather seal and excessive squash deforms it past the seal envelope.

SIZE AND DRILL CAPACITY

14g-10 standard gauge, Tek 4 drill capacity (up to 5mm steel). Common lengths: 55mm for cladding to 2-3mm purlin, 65mm to 5mm purlin, 75mm to deeper structural section. The full length covers the cladding thickness plus the host steel plus 5-10mm thread engagement.

WHY AUSTRALIA TRUSTS BOLT & NUT

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