Screws for Timber

Timber Screws for Framing, Decking, Cladding and Plasterboard

Timber screws thread directly into timber without a pre-drilled pilot in most softwood and treated pine applications. The thread profile, drive type, head form and tip geometry all vary based on the timber-fastening task at hand - decking, framing, cladding, plasterboard or landscape construction. Bolt & Nut Australia stocks the Bremick MultiONE®, Cyclone, Series 500 and BNA ranges from Brisbane: 660+ SKUs covering virtually every timber screw application in Australian residential, commercial and landscape construction.

We've been supplying these online from Brisbane for over 15 years. With 25,000 stock lines and over 200 million pieces in stock, we carry one of the most comprehensive ranges of timber screws available in Australia — from Bremick MultiONE® Torx countersunk truss, T17 self drilling bugle batten, Hex Flange stitching, Wafer stitching, Flat Top, Landscape large-washer-head, Painted COLORBOND cladding and Plasterboard / Villaboard fine-thread bugle heads. Save more as you buy more — we offer up to 13 price breaks plus 3 spend-tier discounts.

HEAD STYLES AND THEIR APPLICATIONS

Bremick MultiONE® (Countersunk Truss Torx T20): the Bremick Revolution range with the patented Multi-One drive system. Torx T20 head, deep-thread profile, sits in a wide range of timber thicknesses without splitting hardwood. The trade-favoured choice for framing where a single screw must work across pine, hardwood, treated pine and engineered timber.

Bugle Batten (In-Hex 5mm): the long-shank, large-headed batten screw - the standard for decking, batten and landscape construction. Hex socket drive for high torque without cam-out. Part-thread design lets the timber pull tight to the joist below. T17 self drilling tip eliminates pre-drilling in most softwood and treated pine.

Hex Flange Stitching (1/4 hex AF): the timber equivalent of the metal Cyclone fastener - hex flange head with a bonded weather washer for sheet-cladding fastening into timber framing. Needle point self drilling tip for thin sheet substrates.

Button & Wafer (Phillips PH2): low-profile heads for sheet-on-timber fastening where a flange would protrude. Needle point self drilling tip handles thin sheet plus timber framing.

Flat Top Stitching (Phillips PH2): minimum-profile head for visible cladding work.

Landscape (Large Washer Head, In-Hex 5mm): oversized washer-head retaining wall and garden-bed timber fastener. 16-gauge shank with part thread. 75mm through 200mm lengths for railway sleeper and large-section timber construction.

Painted (Hex Flange, T17): COLORBOND-colour-matched hex flange screws for fencing, shed and patio cladding into timber framing.

Plasterboard & Villaboard (Phillips PH2 Bugle): bugle-head fine-thread screws for plasterboard, Villaboard and similar lining boards onto timber stud framing.

MATERIALS AND COATINGS

Zinc Yellow (Class 2): zinc plate with a yellow chromate passivation - interior and dry, sheltered work. Galvanised (Class 3, 4, B8 and X9): galvanised finishes for exterior and structural timber fastening, harsher exposure as the class rises. Painted COLORBOND: hex flange head finished to the BlueScope colour chart (NEO Basalt, NEO Classic Cream and the wider COLORBOND range). All variants use Class-rated steel cores for high pull-out and shear strength under load.

COATINGS EXPLAINED — WHAT CLASS 4, B8, DX3, DX4, TYKOTE AND RUSPERT MEAN

Screws come with different coatings to suit different environments. The Australian standard for screws is AS 3566 — the higher the class, the more rust protection. Class 4 is our preferred minimum. We still stock some Class 3 and are slowly moving the range to Class 4. Class 3 is fine for sheds, garages and inland builds. Use Class 4 or higher within 1 km of the coast, or anywhere with salty air, chemicals or industrial pollution.

Class 3 — The long-standing minimum for inland external use. Fine for sheds, garages, rural and suburban inland builds. Still stocked while we transition the range to Class 4.

Class 4 — Heavy-duty zinc with a sealing topcoat. The right choice for coastal builds within 1 km of the surf and most industrial sites. Lasts 15 to 25 years in normal use. Brand variants of Class 4 include Hobson's DX4 (with paint-matched topcoat) and Hobson's X9 (for steel-to-steel and roofing).

Hobson DX3 and DX4 — Hobson's brand names for Class 3 (DX3) and Class 4 (DX4) screws. DX4 comes in paint colours to match Colorbond and standard trade colours. We stock both while we transition the range over to DX4.

Bremick Revolution B8 — Bremick's top coating, twice as protective as Class 4. Built for severe coastal and industrial sites, including beachfront work within 150 metres of breaking surf. Bremick warrants these screws for up to 30 years inland and 10 years on the worst coastal sites. The coating is also 8x harder than Class 4, so it survives the drilling without rubbing off.

Tykote — Hobson's top coating for timber, decking and landscape screws. Built for treated pine, hardwood decking and outdoor timber work in tough coastal or industrial spots. Same protection level as B8 — for timber instead of steel.

Ruspert — A three-layer Japanese coating: zinc + chemical sealer + ceramic top. Comes in three grades — R500, R1000 and R1500. The number is hours of rust testing, so higher means longer life. Handles acid, alkaline chemicals and saltwater better than plain galvanised.

Mechanical Galvanised — Zinc applied cold by tumbling the screws with zinc flakes and glass beads, instead of dipping them in molten zinc. The cold process keeps hardened screws strong (no heat damage). Protection level usually matches Class 4.

What about Class 5? There's no official Class 5 in AS 3566 — the standard stops at Class 4. When you see Class 5 in marketing, it means a coating that goes above Class 4, like B8, Tykote or Ruspert R1000+. We list the actual coating name on each product instead of using a generic Class 5 label.

Which coating for where?

• Inland sheds, garages and rural builds — Class 3 works. Class 4 if you want longer life.
• Suburban or mild industrial areas — Class 4.
• Within 1 km of the surf — Class 4 or higher. Hobson DX4, X9 or Bremick B8 are solid picks.
• Beachfront (within 150 m of breaking surf) or heavy industrial — Bremick B8, Tykote or Ruspert R1000+.
• Not sure? Send us your postcode and we'll match the coating to your site.

View the full coating comparison table ▾

TIMBER-SPECIFIC CONSIDERATIONS

Treated pine: the copper-arsenate (CCA) or copper-azole (LOSP / ACQ) preservative chemistry is mildly corrosive to standard galvanised - use Class 4 Zinc Yellow or higher for any treated-pine application longer than 12 months. Hardwood: generally needs pre-drilled pilot for screws above 10g gauge to prevent splitting; T17 self drilling tips work in most hardwoods up to 10g without pre-drilling. Engineered timber (LVL, glulam): use manufacturer-rated screws; the Bremick MultiONE® range is rated for most engineered substrates.

PILOT HOLE GUIDE - WHEN AND HOW TO PRE-DRILL

Pre-drilling prevents splitting and saves screw heads on dense or treated timber. The decision tree:

NO pre-drill required: softwood (radiata pine, cypress, hoop pine) and most treated pine, when using a T17 self drilling tip OR a needle point tip screw. The T17 cuts its own pilot in front of the thread; the needle point pushes timber fibres aside. This covers ~80% of general decking, framing and batten work.

PRE-DRILL required: dense hardwood (jarrah, ironbark, spotted gum, blue gum, red gum), end-grain installation regardless of species, within 25mm of a board edge, and for screws above 14g gauge in any timber. Hardwood at the screw tip will split if the thread tries to displace too much fibre; end-grain has weaker hold and splits easily; edges have nothing on one side to resist the splitting force.

Pilot drill diameter: 70-75% of the screw shank diameter for softwood (M5 = 3.5mm pilot, M6 = 4.0mm); 80-85% for hardwood (M5 = 4.0mm pilot, M6 = 4.5mm). A shorter pilot (drilling only to the top half of the screw length) preserves bite at the tip while preventing splitting at the entry; a full-depth pilot is faster but reduces pull-out strength.

Special case - Bremick MultiONE®: the deep-thread profile lets the same screw drive in pine, hardwood, treated pine and engineered timber without pre-drilling in most cases. The Torx T20 drive resists cam-out at the high torque hardwood requires. See the Bremick MultiONE® sub-cat for the trade-grade alternative to pre-drilling.

For the full pilot-hole reference across all common species and gauges, see the Technical PDF's Library.

CHOOSING SCREW LENGTH FOR YOUR APPLICATION

Screw length is calculated as the top board thickness plus the engagement length in the base timber. The engagement length follows the 1.5-2x diameter rule: aim for thread engagement equal to at least 1.5 times the screw diameter, ideally 2x for structural connections.

Decking (timber-on-timber): 19mm board on 75mm joist needs ~50mm screw (19 board + 30mm engagement = 49mm total, round up to stocked 50mm). 32mm board on 75mm joist needs 65mm. 45mm board on 75mm joist needs 75mm. Larger 14g shank wants 30-40mm engagement at the bottom; 12g shank wants 25-30mm.

Decking (timber-on-steel): board thickness + steel joist thickness + 15-25mm thread engagement extending past the joist (the part that actually grips the steel via self drilling thread cut). 32mm board on 3mm steel joist needs 32 + 3 + 25 = 60mm screw - the stocked 65mm is the right pick.

Framing (timber-to-timber): 90mm or 100mm screws are the framing standard, covering 35-45mm structural-grade timber face into 90-100mm joist or stud. The Bremick MultiONE® range covers the framing applications where multiple timber types are mixed.

Plasterboard / Villaboard onto stud: the plasterboard screw range covers 25mm (10mm board onto 70mm timber stud or 0.55mm metal stud), 30mm (13mm board onto 70mm stud), and 41mm (double-sheet board or thicker stud). Match length so 15-25mm engages the stud past the back of the board.

Landscape / retaining wall: 75mm, 100mm, 125mm, 150mm and 200mm landscape screws for sleeper-on-sleeper construction. Match length so 30-50mm of thread engagement extends into the base sleeper.

Cladding-to-timber stitching: the Hex Flange stitching screws cover 12mm to 30mm total length - long enough for the cladding plus 8-15mm timber engagement in the stud behind.

Over-length screws waste cost and risk piercing through the back of a thin joist; under-length screws don't develop the engagement needed for pull-out resistance. The rule of thumb above sizes the screw correctly for the common timber stacks in Australian building.

DRIVE BIT SELECTION AND MATCHING

The fastest way to wreck a screw is to use the wrong drive bit. Match the bit to the screw recess exactly - the number stamped on the screw head IS the bit size. Mixing PH and PZ in the same recess, or running an undersized bit in a larger recess, results in cam-out (the bit slipping radially under torque) which strips both the bit and the screw. Once a screw recess is rounded, the only way to extract is a screw extractor or grinding.

Phillips (PH): PH0, PH1, PH2, PH3, PH4. PH2 is the most-used size across timber screws. The Phillips recess is designed to cam-out at design torque - good for hand work, less suitable for impact-driver use where Pozi or Torx tolerate higher loads.

Pozi (PZ): PZ1, PZ2, PZ3. Pozidriv recesses have four radial ribs between the cross arms - tolerates higher torque than Phillips at the same tip size. A Phillips bit in a Pozi recess cams out aggressively; a Pozi bit in a Phillips recess rounds the Phillips. Look at the screw head: cross only = Phillips; cross plus four small ticks = Pozi.

Square (SQ / Robertson): SQ0, SQ1, SQ2, SQ3. SQ2 is the standard size on decking and treated-pine screws. The square geometry resists cam-out at high torque - the workshop preference for impact-driver decking work.

Torx (T): T10, T15, T20, T25, T27, T30, T40. The Bremick MultiONE® range uses Torx T20. Torx tolerates the highest torque of the common drives without cam-out and is the rising trade standard for structural and engineered-timber screws.

In-Hex (5mm): the bugle batten head decking screws and landscape screws use a 5mm internal hex drive. Drives with a 5mm hex bit in a powered driver - no cam-out, accepts the high torque hardwood and sleeper screws need.

For matching driver bits see the Driving section - Phillips, Pozi, Hex, Torx, Square and Slot bits in insert, power and long lengths.

SCREW GAUGE AND TPI

Screws for Timber are sized in Australian / imperial gauge. Most gauges in our range are stocked with several TPI options because timber screws cut across softwood (structural framing, decking, treated pine) and hardwood (jarrah, merbau, ironbark) with different thread requirements. The Thread Profile column tags each TPI variant: coarse threads (lower TPI) bite into softwood; fine threads (higher TPI) cut cleanly into hardwood without splitting. The table below shows the stocked range:

Bolt & Nut Australia stocks 6g through 18g across the timber range. Use the coarse-profile rows for softwood and decking, the fine-profile rows for hardwood, and refer to the per-product TPI on each screw's page for the exact thread pitch of that SKU.

OUR RANGE

Bremick MultiONE® — Bremick Revolution Torx T20 countersunk-truss head, deep thread, the single screw for pine, hardwood, treated pine and engineered timber in framing applications. Available in 80-pack and 250-pack format.

Countersunk Timber Screws — the workshop standard - Bugle Batten head with T17 self drilling tip and In-Hex (5mm) drive. Galvanised Class 4 finish. Sizes 12g and 14g, lengths 50mm through 200mm. The default for decking, batten, fencing and general framing.

Hex Flange Timber Screws — Cyclone-pattern hex flange with bonded weather washer for sheet-cladding into timber framing. Needle point tip. Sizes 8g and 10g.

Button & Wafer Timber Screws — low-profile head sheet-into-timber fasteners. Phillips PH2 drive. Stitching screws for cladding-to-timber-stud work.

Flat Top Stitching Timber Screws — minimum-profile flat-top head for visible cladding-to-timber work where any head projection is unacceptable.

Landscape Timber Screws — large washer-head Bugle Batten screws for retaining walls, garden beds, railway sleepers and large-section timber construction. 16g shank, 75mm through 200mm lengths.

Painted Timber Screws — COLORBOND-matched hex flange screws (NEO Basalt, NEO Classic Cream + colour range) for fencing, shed and patio cladding into timber framing.

Plasterboard & Villaboard Screws — fine-thread bugle-head Phillips PH2 screws in 1000-pack collated format for plasterboard, Villaboard and similar lining boards onto timber stud framing.

Need help choosing the right grade or size? Our Technical PDF's Library has specification guides and technical charts. Prices include GST and free standard delivery anywhere in Australia.

FREQUENTLY ASKED QUESTIONS

Do I need to pre-drill timber for self drilling timber screws?

For pine, treated pine and most softwood, no - the T17 or Needle Point tip drills clean. For dense hardwood (jarrah, ironbark, spotted gum), pre-drill a pilot 0.5-1.0mm smaller than the screw shank to avoid splitting, especially at board ends. For Bremick MultiONE®, the deep-thread profile bites without pre-drill in most timbers including some hardwoods.

What's the difference between T17 and a Needle Point tip?

T17 is a small drill flute ground into the screw tip - it cuts a small pilot hole in front of the thread as the screw runs. Needle Point is a sharp tapered point with no drill flute - it pushes the timber fibres aside and threads in. T17 is the default for general timber work; Needle Point is for stitching applications (thin sheet over timber framing).

Why are Landscape screws so much bigger than other timber screws?

Retaining wall, garden bed and railway sleeper construction uses 100mm+ thick timber that needs a 16g shank and 75-200mm length to engage adequately. Smaller screws would shear under the pull-out loads typical for landscape timber. The large washer head spreads load across the timber face without pull-through.

Can I use timber screws to fasten timber to steel?

No - timber screws are designed for timber-to-timber. The thread profile is optimised for timber bite, not steel cut. For timber-to-steel, switch to the Countersunk with Wings variant or a dedicated self drilling metal screw.

What's the difference between Bugle Batten and Hex Flange?

Bugle Batten has a flat-faced bugle head with In-Hex (5mm) drive - it seats flush in the timber face for a clean visual finish. Hex Flange has an external hex head with bonded washer for high-torque sheet-clamping fastening. Bugle for visible work, Hex Flange for cladding sheet work.

Are Bremick MultiONE® screws really different to other timber screws?

Yes - the patented thread profile, drive geometry and head design lets one screw serve across multiple timbers without splitting hardwood or stripping softwood. For trade users who don't want to stock 3 different screws for 3 different timber species, MultiONE® lets one box cover the job. Pricier than commodity timber screws but reduces SKU count and rework.

Why are plasterboard timber screws fine-thread instead of coarse?

Fine thread cuts more slowly through the timber stud underneath the plasterboard, which gives the installer more time to seat the bugle head accurately at the correct depth (1-2mm below the paper). A coarse thread would over-drive in a single trigger pull and tear the paper. Fine thread = controlled seating.

Can I use galvanised timber screws on treated pine?

For sheltered work yes; for fully exterior or below-DPC work no. CCA-treated pine is mildly corrosive to standard galvanised over time - use Class 4 Zinc Yellow or higher for long-term treated pine work. LOSP (light organic solvent preservative) treated pine is less aggressive but still benefits from higher finish.

Do painted timber screws hold their colour long-term?

The painted hex flange heads match the BlueScope COLORBOND warranty - 10-15 years colour stability typical. UV exposure causes a small colour shift over decades but the shift matches the cladding panel's shift, so the visible result stays consistent. Touch-up paint resolves chip damage.

Where can I find pilot-hole drill sizes for timber screws?

The pilot-hole reference is in the Technical PDF's Library library. Rule of thumb: 70-75% of the shank diameter for softwood (M4 = 3mm pilot), 80-85% for hardwood (M4 = 3.5mm pilot).

How long should a timber screw be?

General rule: the thread engagement in the receiving timber should be 1.5-2 times the screw diameter. For a 5mm shank screw, 8-10mm of thread engagement in the base timber. The total screw length = top-board thickness + bottom-board engagement. For decking on 50mm joist, a 65mm screw with 30mm board gives 30mm of base engagement, ideal.

Where do I see the per-SKU thread length, drive size and finish?

Per-SKU details are on each sub-cat page - see the 8 sub-cats above. For category overview by application (framing vs cladding vs decking vs landscape), see Technical PDF's Library.

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 timber screw.