DeckingPro™ DS65 Decking Screw Technical Specification
Dimensions, Installation & Compatibility for the DeckingPro™ DS65 Decking Screw
DeckingPro™ DS65 is a 4.5 x 65mm double countersunk A2 stainless steel decking screw engineered for face-fixing thicker composite and timber decking boards, stair treads, and high-load applications where greater thread penetration into the subframe is required. See the full range of screws on the DeckingPro™ DS65 decking screws page.
The additional 15mm of length compared to the DS50 provides deeper engagement into the timber subframe, increasing pull-out resistance for boards above 22mm thickness, composite and hardwood joist systems, and fixing locations subject to concentrated load such as stair treads, decking steps, and commercial outdoor platforms. The double countersunk head reduces the risk of head shear and assists completion of countersinking, allowing the fixing to sit flush below the board surface. The helix shank removes debris during installation and improves clamping performance. The single slash point reduces drive torque and minimises the risk of timber splitting at low edge distances, particularly important when fixing boards close to their ends and edges.
DeckingPro™ DS65 screws are powder coated in-house at RALfixings to precise RAL colour specifications, with the electrostatic coating applied to the screw head only. This preserves the full mechanical performance and corrosion resistance of the A2-304 stainless steel base screw while delivering a durable, colourfast head finish that blends with the board surface. Available in 8 RAL colour-matched finishes matched to leading UK decking board colours.
DeckingPro™ DS65 screws are specified by landscape contractors, decking installers, and outdoor fit-out teams for face-fixing thicker decking boards, stair treads, and structural fixing locations where the DS50 does not provide sufficient penetration depth.
Technical specification
| Size (mm) | 4.5 x 65mm |
| Size (imperial) | 9 x 2½ |
| Thread Diameter | 4.5mm |
| Head Diameter | 8.76mm |
| Head Type | Double Countersunk with Ribs |
| Recess Type | Pozi PZ2 |
| Thread Type | 40° Single Deep |
| Thread Coverage | Partially threaded - 65mm |
| Shank Type | Helix |
| Point Type | 25° Sharp with Single Slash |
| Gauge | 9 |
| Material | Austenitic Stainless Steel (A2-304) |
| Head Finish | Powder coated - RAL colour to order (head only) |
| Corrosion Rating | 4 - Urban & industrial areas with a moderate salt atmosphere |
| CE Standard | BS EN 14592:2008 (base screw) |
Key design features
- Double countersunk head with ribs - reduces the likelihood of head shear and assists completion of countersinking, allowing the fixing to sit flush below the board surface for a clean, near-invisible finish
- 65mm length - provides deeper thread engagement into the subframe than the DS50, increasing pull-out resistance for thicker boards, hardwood joists, and high-load fixing locations including stair treads and commercial decking platforms
- Helix shank - removes debris during installation and improves clamping force between the board and the subframe
- Single slash point - reduces drive torque and minimises the risk of timber splitting when fixing at low edge distances, such as board ends and perimeter fixings
- A2-304 stainless steel - provides strong corrosion resistance for standard UK outdoor environments including decking platforms, balconies and terraces
- Powder coated head (head only) - electrostatic process produces a durable, UV-resistant colour finish matched to the board surface; coating applied to the head only, preserving full mechanical integrity of the stainless steel thread and shank
Intended applications
DeckingPro™ DS65 screws are designed for face-fixing applications where increased thread penetration is required, including thicker composite and timber boards, stair treads, hardwood subframe systems, and commercial outdoor decking.
- Composite decking boards 25mm and above - face fix to timber or steel subframes
- Stair treads and step fixings - where pull-out resistance under load is critical
- Composite and hardwood joist systems - deeper thread engagement for structural fixing
- Fascia boards and perimeter decking edges on thicker-profile systems
- Riser boards and decking stair strings
- Softwood and hardwood timber decking boards
- Commercial outdoor decking platforms and high-traffic walkways
- Balcony and terrace decking where clip systems cannot be used
When to use DS65 instead of DS50
For standard 20 to 22mm composite or timber decking boards on softwood joists, the DS50 provides sufficient penetration depth and is the standard specification. Use DS65 when:
- Board thickness is 25mm or greater
- Fixing into hardwood or composite joist systems where greater pull-out resistance is required
- Installing stair treads and step fixings subject to concentrated foot traffic load
- Working on commercial decking platforms where structural fixing margins are specified
- Fixing perimeter or fascia boards on thicker-profile composite systems
Substrate compatibility
DeckingPro™ DS65 is suitable for use with composite and timber decking boards fixed to a range of subframe materials. A2 stainless steel is required where fixing into corrosive timber species.
- Composite decking boards - all standard UK hollow and solid composite board profiles, particularly boards 25mm and above
- Softwood joists and subframes - treated and untreated softwood timber (C16, C24)
- Hardwood joists and subframes - including oak, iroko, and hardwood decking frameworks where deeper thread engagement is required
- Corrosive timber species - green oak, cedar, sweet chestnut, and other tannin-rich timbers where stainless steel is required to prevent staining and chemical corrosion of the fixing
- Softwood and hardwood decking boards - suitable for face-fixing solid timber decking in matching or contrasting RAL colour finishes
- Steel decking subframes - pre-drilling recommended for light gauge steel framing
Installation guidance
- Use a variable-speed cordless or mains driver with a PZ2 bit
- Set clutch to avoid overdriving - the double countersunk head should sit flush with or just below the board surface
- Pre-drilling is not required in most standard decking board and softwood joist applications
- For hardwood joists or fixings within 15mm of board edges, a 3.5mm pilot hole is recommended to prevent splitting
- Recommended fixing centres: 300 to 400mm per board
- Minimum edge distance: 15mm from board edge
- Minimum end distance: 25mm from board end
- For stair tread fixing, allow 6 to 8 screws per tread depending on tread width and joist layout
- Ensure decking subframe is level, structurally adequate and correctly spaced before installation
- Do not use with incompatible coating systems or preservatives that may react with stainless steel
Corrosion & durability
DeckingPro™ DS65 is manufactured from A2-304 austenitic stainless steel, providing strong corrosion resistance suitable for standard UK outdoor decking environments. The powder coated head provides an additional protective layer at the exposed fixing face.
- A2-304 stainless steel core - corrosion resistant throughout the full shank and thread
- Corrosion rating 4 - suitable for urban and industrial environments with moderate salt atmosphere
- Powder coated head - UV-resistant, weather-resistant finish with improved long-term colour retention compared with painted or dip-coated alternatives
- Stainless steel grade ensures compatibility with corrosive timber species including green oak and cedar, where zinc or carbon steel fixings will corrode and stain
- Suitable for standard UK residential and commercial outdoor decking installations
Colour availability
DeckingPro™ DS65 screws are available in 8 RAL colour-matched finishes, each physically matched to the dominant tone of leading UK decking board colours. All 8 colours are stocked for same or next working day dispatch. Colour specifications are identical to the DS50 range, ensuring complete visual consistency when both lengths are used on the same project.
- RAL 1015 - Light Ivory
- RAL 1019 - Grey Beige
- RAL 7009 - Green Grey
- RAL 7016 - Anthracite Grey
- RAL 7035 - Light Grey
- RAL 7042 - Traffic Grey A
- RAL 8019 - Grey Brown
- RAL 8028 - Terra Brown
For colour matching guidance see the DeckingPro™ DS65 colour matching guide.
Packaging & supply
DeckingPro™ DS65 screws are supplied in the following retail pack sizes:
- 25
- 50
- 100
- 200
- 500
Trade account holders can access the following volume pack sizes at trade pricing:
- 200
- 500
- 1,000
- 2,000
Each pack is labelled by RAL colour code and product reference.
Suggested specification wording
Fixings for decking boards shall be DeckingPro™ DS65 Colour-Matched Decking Screws, 4.5 x 65mm, double countersunk with ribs, helix shank, single slash point, A2-304 austenitic stainless steel, powder coated head in RAL [colour code] to match decking board. Minimum fixing centres 300mm. Supplied by RALfixings Ltd, Pro Colour Group Ltd.
Technical support
DeckingPro™ is a colour-matched decking fixing system supplied by RALfixings Ltd. Trade, project and specification support is available including:
- Project quantity calculations
- Colour matching guidance against specific board brands and colourways
- Stock colour availability confirmation
- Trade account pricing
- Specification assistance for landscape and outdoor construction projects
For technical support or specification assistance please contact info@ralfixings.com.