SoftWood Clip

Hidden fasteners for heat-treated wood

Registered trademark

  • 1. Screwing of deck boards onto joists at a 45° angle – Self-tapping screws in A2 stainless steel
  • 2. Symmetrical profile allowing for reversible boards
  • 3. Integrated spacing wedge
  • 4. Integrated screw guide for 45° angle
  • 5. Pre-grooved or grooved using grooving machine

Made from highly efficient revolutionary polyamide resin.

SoftWood Clip is unbreakable and highly resistant.

1. Highly efficient revolutionary polyamide resin
  • Unbreakable.
  • Superior mechanical resistance.
  • Extreme toughness guarantees that the screw does not pierce the fastener during screwing.
  • Wood swelling and shrinking absorption capacity with memory.

Screw guide integrated into the SoftWood Clip.

Innovative design for exceptional ease and speed of installation.

  • 1. Screw openings with integrated 45° screw guide
  • 2. Design for the perfect integration of the screw head
  • Guarantees the perfect screwing angle.
  • Keeps the screw in place during installation,
  • making it even easier and faster.
  • The shape of the openings is designed for the perfect integration of the screw head without risk of piercing.

Screwing of deck boards onto sleepers.

The boards are screwed into the sleepers at an angle of 45° through the SoftWood Clip fastener..

  • Guarantees perfect assembly of deck boards and sleepers.
  • Guarantees the solidity and stability of the decking.
  • Controls the lengthwise locking of the boards.
  • Controls the direction of wood movement.
  • Guarantees the alignment over time of the boards installed end-to-end.
  • Guarantees the permanent clamping of the deck boards onto the sleepers.

Controls wood movement.

Perfect alignment of the boards and regular spacing.

  • 1. Direction of the swelling of the boards
  • 2. Direction of the shrinking of the boards
  • 3. Fitted side of the boards
  • 4. Screwed side of the boards
The same side of the boards is screwed onto the sleepers (4). The opposite side (3), on the other hand, is firmly fitted against the sleepers using the fasteners. During swelling and shrinking of the boards, the wood will naturally choose the easiest and most accessible way to move, i.e., in the direction opposite the screwed side (see illustration above). Therefore the regular and constant spacing between boards can be guaranteed over time, as well as the alignment of the boards installed end-to-end.

Integrated spacer wedge.

The spacing between boards is automatic and regular.

hardwoodclip-cale-ecartement-11. Spacer wedge in high-performance plastic resin
  • 1. Two wedge sizes to guarantee the correct spacing between boards (5 mm-7 mm).
  • hardwoodclip-cale-ecartement-2
  • 2. Absorbs the swelling of the wood without damaging the edge of the boards.
  • hardwoodclip-cale-ecartement-3
  • 3. Innovative design guarantees superior strength of the fastener during installation.
  • 4. Memory material that resumes it shape and size when the boards return to their initial dimensions.

Anti-slip system.

Gripping ribs to keep the fastener in place while screwing.

  • Prevent the fastener from moving while screwing.
  • Guarantee the stability of the fastener in the groove and its horizontal position.

1. Anti-slip and stability corrector system


Reversible and symmetrical boards.

Both sides of the boards can be used.

  • Smooth surface/Ribbed surface Stock reduction : one stock allows to satisfy all customers’ needs.

  • Two smooth sides Less loss : Both sides can be used, which allows to reduce losses, to choose the installation direction and to select the most attractive side.

The majority of boards shaped to receive an invisible fastener are not reversible as their profile is asymmetrical and sometimes unidirectional. Only one side of the boards can be used. If the top side is damaged, it cannot be used and is lost.

Contrary to other hidden fastening systems, the HardWood Clip grooved surface on the other hand, is perfectly symmetrical and reversible.

Both sides of the boards can be used, regardless of the side.

As a result the quality is improved, installation made easier and losses reduced.

Board replacement.

Several methods described in our instructions manual.

SoftWood Clip fasteners allow to replace one board without being obliged to dismantle the entire structure. Several methods are described in detail in our “Board replacement” guide, which can be downloaded from our website.

Wide variety of applications.

Designed to cover a vast array of applications using stables wood species, with very low internal stresses.

Species green-circle
Board thickness* From 20 mm.
Board width* Any board width up to 145 mm. Respect the width/thickness ratio required for the species. Beyond that, on a case by case basis. Combining widths is possible on the same structure.
Decking green-circle
Weatherboarding green-circle
Diagonal layout of the boards green-circle
*Scrupulously respect the requirements linked to the chosen species (NF B 54-040), the requirements of the standards and regulations in force (notably NF-DTU 51.4 and 41.2), maximum width/thickness ratio values, installation and grooving instructions, regulations in force and good practices.

Fast and easy to install.

30 to 40% faster.

SoftWood Clip allows to save at least 30 to 40% in installation time (outside of structure) compared to traditional installation, whilst offering greater durability and safety as well as guarantees in terms of resistance and stability to the equivalent minimums. SoftWood Clip is also easier and faster to install than the majority of existing hidden fasteners.

With the SoftWood Clip fastening system, three long and tedious steps are eliminated:

• Fitting of spacer wedges between all boards
• screw alignment using chalk line on each sleeper
• Measurement and marking of the location of all screws

And two are cut in half:

• Pre-drilling and countersinking of all screw holes
• Screwing of two screws at each assembly point

In fact, by using SoftWood Clip, the position of the fastener, the gaps between boards, the screwing of the fasteners are performed in a single step. What is more, a single fastener is necessary for each assembly of a board and sleeper (2 screws obligatory in traditional installations).

The quality of design and manufacture of each of the SoftWood Clip fastener system’s components guarantee exceptional ease and efficiency for the installer.

Traditional installation

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SoftWood Clip


SoftWood Clip preserves wood fibres.

SoftWood Clip considerably reduces the risk of splitting linked to the wood’s natural movements.

Use of the SoftWood Clip fastening system protects the wood fibres against aggression and stress it undergoes with traditional installations and raised screws, when the boards swell and shrink widthwise, between dry and wet seasons.
In fact, with traditional raised screws, the boards are secured with two screws, widthwise, which cross it to fix it firmly in place on the sleeper and prevents any movement.
But when the wood swells and shrinks, it will exert considerable force and pressure on the screws that cross it. Its fibres will get damaged and weakened and will lead to splitting and warping. In some cases as well, the screws may break under this major stress.

  • 1. Direction of stress exercised on the wood fibres and screws
  • 2. Major stress on wood fibres during swelling, shrinking and movement of the boards.
  • 1. Direction of the swelling of the boards
  • 2. Direction of the shrinking of the boards
  • 3.Fitted side of the boards
  • 4. Screwed side of the boards
Thanks to the tried-and-tested screwing principle of SoftWood Clip fasteners, no stress is exerted on wood fibres, which are preserved during swelling and shrinking. Board movement is controlled and always takes place in the same direction, opposite the screwed side, without the least aggressive obstacle.

Superior durability compared to traditional installation.

The integrity of the board surface is preserved and multiple water penetration points into the wood are eliminated.

The use of hidden SoftWood Clip fasteners allows to eliminate screw holes in the surface, which constitute multiple retention points through which water and dirt penetrate the wood. SoftWood Clip also eliminate the risk of splitting and deterioration on the board surface, in screwing points, which also are a source of water penetration into the wood.

SoftWood Clip (Twin profile)


Traditional installation with raised screws: multiples penetration and water retention points.


Exceptional stability.

Each board is directly screwed into the sleepers.

Contrary to other existing hidden fasteners, SoftWood Clip is the only hidden assembly system that screws each screw directly into the sleepers. Thus screwed, the boards are firmly locked in place.

No lengthwise board movement is possible. They are safely secured to the structure with a force a lot greater than the requirements imposed by the standards in force.


Unequalled safety.

Eliminates risk of injury.


SoftWood Clip removes the risk of injury caused by the surface of the wood damaged by screwing or by raised screw heads in traditional installations.

SoftWood Clip also removes the risk of burns to the feet that may be caused by screw heads heated by the sun.

Top-notch design.

Only quality is visible.

No fastener and no hole are visible. The boards surface remains perfect. The anti-reflection coating and the black colour of the SoftWood Clip fasteners as well as the antique brown stainless steel of the screws guarantee perfect discretion between boards and absorb light and sun rays.

Thanks to its integrated spacer wedge and its principle of control over wood movement, SoftWood Clip is the only fastening system that guarantees regular and constant spacing between all boards over time, contrary to other hidden fasteners or to traditional installations.


Exclusive self-tapping SPAX screw® in stainless steel A2.

Exceptionally efficient with Thermowood® and heat-treated wood.

  • 1. SPAX ground serrations profile
  • 2. CUT SPAX point
  • 3. Ground serrations
  • 4. Small raised head
  • 5. Torx T15 SPAX T-STAR plus
  • 6. Solution-dyed “Antique” brown
  • Exclusive: developed by the world leader SPAX® jointly with ARCHI WOOD, the screw is exclusive to HardWood Clip® and other NÖVLEK fasteners®.
  • Stainless A2 II: stainless steel, manufactured in Europe, of exceptional quality, with anti-friction coating and very high anti-corrosion protection.
  • CUT SPAX point very precise positioning of the screw, allows screwing without pilot hole (refer to our installation instructions) and effectively reduces splitting of the wood.
  • Small head: designed in order not to damage the side of the board, it guarantees both maximum discretion and high mechanical resistance.
  • Torx T15 SPAX T-STAR plus TORX T-STAR plus drive was designed by SPAX® to guarantee the optimal housing of the bit, without cam-out effect, promoting optimal torque transfer.
  • Screw thread with SPAX ground serrations: guarantees rapid and secure screwing.
  • “Antique” brown colour: stainless steel is solution-dyed during the screw’s manufacturing process. Guarantees maximum discretion and considerably reduces light reflection or sun rays.
  • MULTI head with ground serrations: slows down the screw when it is hits the fastener’s stainless steel reinforcement.
  • ETA-12/0114: self-tapping SPAX screws® have received European Technical Approval.
  • Made in Germany: the screw is manufactured in Germany, as are all SPAX products ®.

Torx T15 SPAX T-STAR plus

Optimal housing for the bit and best guidance.
  • High adjustment precision.
  • High hardness.
  • Perfect transmission of tightening torque.
  • Long service life.

Small head.

Designed for NÖVLEK fasteners® in order to ensure optimal tightening, whilst guaranteeing maximum unobtrusiveness without damage to the sides of the boards.


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  modele-l hardwood-clip-img-L hardwood-clip-7mm


Kit-Hardwood Clip

CLASSIC ± 12 m2*

Kit contents:
  • 200 SoftWood Clip fastenersTM
  • 200 SPAX screws®
  • 2 TORX T-STAR plus drill bits (50 mm)
  • 1 HSS drill Ø 3 mm
  • 1 instructions sheet
Approximate covered surface
Board width 100 mm 120 mm 140 mm
Surface covered with 1 CLASSIC kit ** approx. 8.5 m2 approx. 10 m2 approx. 12 m2

MINI approx. 6m2*

Kit contents:
  • 85 SoftWood Clip fastenersTM
  • 100 SPAX screws®
  • 1 TORX T-STAR plus drill bit (50 mm)
  • 1 HSS drill Ø 3 mm
  • 1 instructions sheet
Kit-HardWood Clip Ciffre Pro
Approximate covered surface
Board width 100 mm 120 mm 140 mm
Surface covered with 1 MINI kit ** approx. 3 m2 approx. 4 m2 approx. 5 m2
* Board width: 140 mm **Spacing between boards: approx. 40 to 45 cm

SoftWood Clip fastening


Dimensions & Specifications

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Spacing between boards 3-4-img02 3-4-img02
Maximum allowed swelling 4 mm 6 mm
Maximum allowed shrinking 9 mm 8 mm
Material Polyamide technique High impact Polyamide technique High impact
Colour Black Black
Condition of surface Anti-reflection Anti-reflection
UV resistance yes yes
Resistance to high temperatures Excellent Excellent
Resistance to low temperatures Excellent Excellent

SPAX screw®




Dimensions & Specifications



Material Stainless steel A2 AISI 304
Diameter 4 mm
Length 45 mm
Torx T15 SPAX T-STAR plus
Colour Antique brown
Corrosion resistance Very high
Technical specifications of grooves
Thickness of the boards* Any board thickness from 20 mm.
Width of the boards* Any board width up to 145 mm. Respect the width/thickness ratio required for the species. Otherwise, on a case by case basis, depending on the species, thickness, installation conditions, etc. Combining widths is possible on the same structure.
*to be adjusted on a case-by-case basis, depending, notably on the species, width, boards, environment, exposure and climate conditions.



Symmetrical and reversible.

The TWIN profile is perfectly symmetrical and reversible. Both sides of the boards can be used.

Depending on the finish on the boards, the TWIN profile allows to reduce board stock (1 smooth side/1 grooved side or 2 sides grooved differently) or to reduce losses by choosing the best side during installation (2 smooth sides or 2 identical grooved sides). The TWIN profile can be easily created during moulding or in the workshop, with a moulding machine by using a simple blade (without internal rounded corners, in this case), moulding knives or milling cutter. It can also be created on site, during installation, using a Lamello® or similar. If used as weatherboarding, the boards could be more or less cut out depending on the choice of fastening model, conditions and compliance with regulations permitting. 3-5-img02
Applications: decking, weatherboarding and outdoor structures
  • 1. Slight rounding at the outer edge for a perfect finish and to prevent any risk of splitting and splinters
  • 2. Rounded interiors for the perfect positioning of the screw head and facilitate the insertion of the next board
  • 3. Symmetrical “V” groove to prevent any risk of stagnant water


_(non-exhaustive list)




Profile with cover for weatherboarding and decking.

The DROP profile allows to visually reduce spaces between boards whilst guaranteeing adequate spacing provided by HardWood Clip fasteners® or SoftWood Clip fastenersand necessary to the movement of the wood. When used as weatherboarding, the boards could be more or less cut out depending on the choice of fastening model, conditions and compliance with regulations permitting.


Applications: decking, weatherboarding and outdoor structures
  • 1. Slight rounding at the outer edge for a perfect finish and to prevent any risk of splitting and splinters
  • 2. Tongue with drip strip for use with weatherboarding
  • 3. Rounded for perfect cover



Grooving using milling machine (Lamello type)®)

Grooving using the milling machine is recommended for unstable wood species. It also constitutes an alternative when pre-grooved boards are not available.


Simplified installation diagram



Screwing of weatherboarding into beams.

The boards are screwed directly into the beams at a 45° angle through the fastener.

  • The screwing of the boards into the beams guarantees perfect stability of the boards during installation, notably for vertical weatherboarding.
  • Guarantees the stability of the weatherboarding.
  • Controls the lengthwise locking of the boards, notably for vertical weatherboarding.
  • Controls the direction of wood movement.

Ease and time saving during installation thanks to the spacer wedge integrated into the fastener.

The fastener’s integrated spacer guarantees the regularity and consistency of the gaps between all boards during installation.

Thanks to the spacer wedge integrated into the SoftWood Clip fastener, it is not necessary to check the alignment of each of the boards before securing them.

Once the first board is secured, the spacer wedge guarantees constant and regular spacing. A one-off inspection is all it takes.

Choice of 2 notches.

Desired beauty thanks to two fastener models.

The weatherboarding can be closed or cut out, fastener model chosen, conditions and compliance with regulations permitting.


Simplified installation diagrams.


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