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ASSY® 4 WH washer head screw Steel zinc plated partial thread washer head
Partial-thread screw with large washer head washer head for wood-wood fastening in a structural wood construction which must be pulled together in indoor dry or sheltered areas
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Ideal power transmission thanks to RW drive
- More power due to larger contact area at the bit
- More stability, one-handed working, precise positioning due to the tight-fit recess and perfect fit of the bit
- Fewer bit changes, one bit for many screw diameters
- Compatibility with previous AW drive
Visually appealing screw connection on wood surface
- Very high head pull-through values and strong tightening effect thanks to a large head diameter
Significant reduction in the amount of force required when fastening in the screw
- Less splitting when immersing the shank due to the displacement milling effect of the milling shank
- Minimised risk of screw breakage due to high breaking torque
- Reduced risk of injury from protruding metal chips due to the integration of the milling shank into the thread
- High protection of the application tools
No over-tightening or stripping and high feed
- Higher power transmission in hardwoods due to reinforced, asymmetrical thread flank geometry of the coarse thread
- Better anchoring thanks to higher thread flanks
Smooth thread start ensures optimised recessing and biting of the screw
- Reduced splitting effect due to displacement effect of the dome-shaped milling elements in the tip
- Friction-reduced thread rotation allows reduction of the screw-in force to be applied
High strength values and ductility
- Adjusted heat treatment guarantees high strength values and high ductility
- We recommend using the Würth software or the corresponding design aids for planning and dimensioning your assembly. Dimensions of the ASSY screws can be carried out in the Würth timber construction software from a ∅ of 5 mm
- Do not use the screw in applications with direct exposure to the elements or in humid rooms with atmospheres containing chlorine gas. If used outdoors and in rooms that are constantly exposed to high humidity, please use ASSY 4 A2 WH or ASSY 4 A2 BP stainless steel screws
- ASSY 4, ASSYplus 4 and ASSYplus 4 FT chipboard screws are optimised for use in wood and wood materials. For applications in plastic anchors where load capacity can also be reduced, use only screws without an optimised thread tip (tip with milling ribs, drill tip, self-clearing groove etc.), such as the ASSY D screws with countersunk head or pan head
ETA-11/0190 approved
The requirements of the European Technical Approval (ETA) must be observed
For wood-wood connections designed to pull together
The partial thread starting immediately below the shank allows for wood-wood connections designed to pull together. The screw thread is positioned entirely in the lower component once screwed in.
For applications in utilisation class 1 and utilisation class 2 (from ∅ > 4 mm)
- High-quality surface protection, zinc, blue-passivated chromium(VI)-free 8 µm layer thickness
- Suitable for use in utilisation class 1 (interior) and from ∅ > 4 mm in utilisation class 2 (covered outdoor area) according to EN 1995-1-1:2010-12 + DIN SPEC 1052-100:2013-08
- The requirement of classification T2/C2 is fulfilled in accordance with prEN 14592:2017 (D)
- ASSY screws are approved for quasi-static loads
- For optimum use of the screw, the right-size RW bit must be used
- Partial-thread screws are ideal for connecting wooden components. To achieve optimum assembly of the components, the components to be fixed must not be thicker than the length of the shank
- For long screws arranged in a cross shape or in a screw block with narrow edge clearances, it is advisable to drill pilot holes or use a screw-in aid to avoid intersecting of the screws
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