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Decking Timber Screws

Decking Timber Screws

Decking Timber 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 (an 8g screw measures about 4.2mm). Screw gauges have a wider tolerance than bolts, so treat it as a close match rather than exact. Then measure the length - countersunk timber screws are measured overall, head included.

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. Rule of thumb for timber: coarse threads for softwood and framing, fine threads for hardwood.

T17 timber screw side profile showing where to measure

T17 timber screw - gauge is measured across the thread.

Decking timber screws fix deck boards down to timber joists with a countersunk, ribbed head that self-embeds flush into the board without a pre-drilled countersink. The T17 self-drilling point cuts in without splitting, and the part-thread pulls the board tight to the joist to stop movement and squeaks.

For the full dedicated range and coatings, see our Screws for Decking category.

GRADES AND MATERIALS

Stocked in G304 and G316 stainless and Class 4 coated carbon steel. Stainless and Class 4 are the correct choice for treated pine (which is corrosive to plain steel) and for coastal or exposed decks.

DRIVE AND INSTALLATION

In-Hex (Allen) or square drive for grip at the head. The T17 tip means no pilot hole in softwood; pre-drill hardwood boards like merbau and spotted gum to prevent splitting at the board end.

SIZE AND THREAD

Gauges 8g to 12g, lengths to suit 19mm and 22mm boards into 45mm-plus joists. Coarse thread for grip in softwood; choose a length that drives at least 30mm into the joist.

WHY AUSTRALIA TRUSTS BOLT & NUT

With 15+ years selling fasteners online from Brisbane, we hold over 25,000 stock lines and 200 million pieces - 98.75% of online orders placed before 1pm leave same day. Save more as you buy more - we offer up to 13 price breaks plus 3 spend-tier discounts. Read our customer reviews or get in touch if you need help picking the right decking timber screw.

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